What Is The Most Venomous Spider In The World?

In the realm of venomous creatures, spiders have long captivated our fascination and fears. Among them, two arachnids stand out as formidable contenders for the title of the world’s most venomous spider: the Brazilian Wandering Spider and the Sydney Funnel-web Spider. These venomous rivals have garnered attention for their potent toxins and the potential dangers they pose to humans. Let’s explore the characteristics and venomous prowess of these two notorious spiders.

The Brazilian Wandering Spider

Hailing from the tropical regions of Central and South America, the Brazilian Wandering Spider (Phoneutria spp.) has earned a reputation for its highly toxic venom. Known as the “armed spider,” it showcases remarkable adaptability and defensive behavior. The venom of the Brazilian Wandering Spider contains potent neurotoxins that affect the nervous system, leading to a range of symptoms, including severe pain, increased heart rate, sweating, and potential respiratory distress. While bites are relatively rare, the venom’s potency and potential systemic effects place this spider in the spotlight.

The Sydney Funnel-web Spider

Australia’s very own venomous heavyweight, the Sydney Funnel-web Spider (Atrax robustus), enters the scene with its own claim to the title. This arachnid is renowned for its potent venom, particularly in males. Found in the Sydney region and surrounding areas, the Sydney Funnel-web Spider delivers a bite that can cause significant health issues. Its venom is rich in neurotoxins that target the nervous system, leading to symptoms such as muscle spasms, increased blood pressure, and difficulty breathing. While encounters with this spider are relatively rare, its venomous reputation remains well-established.

The potency of the venom possessed by both the Brazilian Wandering Spider and the Sydney Funnel-web Spider is unquestionable. Both species boast highly toxic venom compositions, posing significant risks if bitten. Their neurotoxins wreak havoc on the nervous system and can result in severe symptoms that demand immediate medical attention.

The Verdict

Which spider truly deserves the title of the world’s most venomous? The Brazilian Wandering Spider and the Sydney Funnel-web Spider constantly vie for the top position, showcasing similar venomous prowess and potential dangers. Well, according to Guinness World Records, the most venomous spider is the Atrax robustus (Sydney Funnel-web Spider)(1), with this species’ venom being lethal to primates (including humans) at just 0.2 mg/kg. That’s only 0.0002 grams of venom to be lethal, now that venomous!

Whether you reside in the tropical regions of Central and South America or in the Sydney region of Australia, it is essential to exercise caution and take appropriate measures to minimize encounters with these venomous spiders. Shake out shoes and clothing, and be mindful when handling items stored outdoors. Seek professional help for spider removal if necessary, and educate yourself about the unique spider species in your area.


The Brazilian Wandering Spider and the Sydney Funnel-web Spider undoubtedly command attention as two of the world’s most venomous spiders. Their highly toxic venoms, rich in neurotoxins, make them formidable adversaries. While their venomous potency may be similar, the title of the world’s most venomous spider goes to the Sydney Funnel-web Spider. As we navigate the world of venomous creatures, it is crucial to respect these spiders’ potential dangers and take necessary precautions when coexisting with them in their respective habitats.

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