Australia’s “Most Venomous Snake” Debate
Top 10 by LD50 (Plus Bite Risk & First Aid)

Every summer (usually right after someone spots a brown snake), the same pub debate pops up: “What’s the most venomous snake in Australia?” In WA, you’ll often hear “the gwardar” said with total confidence — and honestly, that makes sense. It’s a fast, serious brown snake, and the name gets repeated so often it turns into “fact”. But “most venomous” depends on what you mean. By lab venom potency (LD₅₀) the Inland Taipan sits at the top. By everyday risk to people, it’s usually brown snakes that cause the most trouble nationally (and in the south‑west of WA, that often means dugites and gwardars).

What “most venomous” actually means (and what it doesn’t)

When scientists compare venom potency between species, they often use a lab measure called LD50 (median lethal dose). In plain terms: it’s how small a dose is needed to be lethal in a standardised test (usually in mice). Lower LD50 = more potent venom. [1]

But real-world danger to humans also depends on things like: how often people encounter the snake, how defensive it is, how much venom it can inject, and how quickly first aid and antivenom are given. Australia has strong medical care and antivenoms, so deaths are rare—but snakebite still needs fast, correct first aid. [4] [2]

Typical bite numbers in Australia (context)

• Estimates often cited are roughly 500 to 3000 bites per year in Australia, with 200 to 500 requiring antivenom. [2]
• Fatalities are uncommon—often described as between 1 and 4 deaths per year in modern times, with brown snakes responsible for most deaths. [2] [3]

Top 10 venomous land snakes in Australia

This list is focused on land snakes and is ranked mainly by venom toxicity (LD50-style potency), then “reality checked” with bite risk and medical significance. Exact LD50 numbers can vary by study, test method, and population—so we keep the ranking clear and the wording honest.

#	Snake	LD50 potency (mouse, s.c.) mg/kg, 0.1% bovine serum albumin	Where you’ll run into it (typical)	Bite risk to people (plain)	Danger terms (plain)
1	Inland Taipan Oxyuranus microlepidotus	0.010 [1]	Remote inland (arid / semi‑arid). Human bites are rare.	Very low (because encounters are rare)	Extreme venom potency, low encounter rate
2	Eastern Brown Snake Pseudonaja textilis	0.041 [1]	Widespread in eastern & parts of southern Australia; farms, urban edges.	High nationally (common around people)	High-risk because it’s often near people
3	Coastal Taipan Oxyuranus scutellatus	0.064 [1]	Northern & eastern coastal tropics/subtropics.	Moderate (range overlaps people in the north)	Severe envenoming potential
4	Tiger Snake group Notechis spp.	0.099–0.271 (regional variation) [1]	Southern Australia & Tasmania; often wetlands/coastal areas.	Regional “frequent biter” in some southern areas	High medical significance
5	Common Death Adder Acanthophis antarcticus	0.338 [1]	Many habitats; camouflage + “sit‑and‑wait”.	Lower than browns, but bites can be severe	High danger if bitten
6	Gwardar / Western Brown Pseudonaja mengdeni (Western brown complex)	0.338 (listed as P. nuchalis “gwardar” in 1979) [1] [2]	Wide across WA/NT/SA (often arid & semi‑arid). In WA, commonly discussed alongside dugites.	Localised; can be common in parts of WA	Life‑threatening bite possible
7	Lowland Copperhead Austrelaps superbus	0.500 [1]	Cooler south‑east mainland & Tasmania; damp areas.	Moderate in its range	Medically significant
8	Dugite Pseudonaja affinis	0.560 [1]	South‑west WA (incl. peri‑urban edges around Perth).	High in SW WA (very commonly encountered)	Major SW WA risk
9	Rough‑scaled Snake Tropidechis carinatus	1.09 [1] [3]	Coastal northern NSW to south‑east QLD (most confirmed bites in that coastal band).	Uncommon overall; serious in its range	Severe coagulopathy risk in its area
10	Mulga / King Brown Pseudechis australis	1.91 [1]	Huge inland distribution (most of Australia).	Moderate in arid regions	Serious due to big venom yield

If you get bitten: the one thing that matters most

Don’t “tough it out”, don’t cut/suck/ice it, and don’t drive yourself around. The recommended Australian approach for suspected venomous snakebite is the Pressure Immobilisation Technique (PIT): apply a firm bandage, immobilise the limb, and get urgent medical help. [4]

Photo guide (because people love images)

Why “Eastern Brown = most dangerous” is a fair shorthand

Even though the Inland Taipan wins the lab-potency contest, the Eastern Brown is widespread and often encountered, and modern case series show brown snakes account for the majority of snakebite deaths in Australia. In the south‑west of WA specifically, hospital data has long shown the dugite is a major culprit in envenoming cases around Perth.

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For practical, local advice specific to Morangup and the Perth Eastern Hills — including seasonal activity, pet safety, pressure immobilisation first aid, local snake bite kits and Country Ambulance Cover — read: Snake Season Advice – Morangup & Perth Eastern Hills

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References & image credits

1. Broad AJ, Sutherland SK, Tanner C, Covacevich J. Toxicity of venoms from some Australian serpents (1979). LD₅₀ values quoted on this page come from mouse subcutaneous assays (18–21 g) using 0.1% bovine serum albumin diluent. Source (PDF)
2. Isbister GK. Snake bite: a current approach to management. Australian Prescriber (2006). Includes commonly-cited Australian incidence estimates and notes modern deaths are uncommon, with most due to brown snakes. Source
3. Johnston CI, et al. The Australian Snakebite Project, 2005–2015 (ASP‑20). Medical Journal of Australia (2017). Reports 23 deaths over 2005–2015 (median two per year), mostly from brown snakes. Source
4. ANZCOR Guideline 9.4.8: Envenomation – Pressure Immobilisation Technique. Source
5. Jelinek GA, et al. Admissions for suspected snake bite to the Perth adult teaching hospitals, 1986–89. Medical Journal of Australia (1991). Notes the dugite caused most envenomations in the Perth cohort. PubMed
6. Australian Institute of Health and Welfare (AIHW). Venomous bites and stings 2017–18 (data). Source
7. Australian Museum. Western Brown Snakes (covers the Western brown complex and common names including “gwardar”). Source
8. Gan M, et al. Envenoming by the rough‑scaled snake (Tropidechis carinatus): a series of confirmed cases. Medical Journal of Australia (2009). Reports most confirmed cases in coastal northern NSW to south‑east QLD. Source
9. Image credit: Wikimedia Commons — Pseudonaja textilis - Nerrigundah.jpg. Source
10. Image credit: Wikimedia Commons — Fierce Snake-Oxyuranus microlepidotus.jpg. Source
11. Image credit: Wikimedia Commons — Taipan (Oxyuranus scutellatus) (10113100415).jpg. Source
12. Image credit: Wikimedia Commons — Eastern Tiger Snake (Notechis scutatus) (8398218886).jpg. Source
13. Image credit: Wikimedia Commons — Acanthophis antarcticus.jpg. Source
14. Image credit: Wikimedia Commons — Pseudonaja mengdeni 260525547.jpg. Source
15. Image credit: Wikimedia Commons — Lowland Copperhead (Austrelaps superbus) (9284112768).jpg. Source
16. Image credit: Wikimedia Commons — Pseudonaja affinis 99437133.jpg. Source
17. Image credit: Wikimedia Commons — Tropidechis carinatus-0124.JPG. Source
18. Image credit: Wikimedia Commons — Pseudechis australis ugmedia.jpg. Source