Tityus serrulatus is considered the most dangerous scorpion in South America and responsible for most of the fatal cases. This review will focus on Tityus serrulatus scorpion venom (Tsv), its long-chain Na(+)-channel toxins (NaTx), which include alpha- and beta-neurotoxins, short-chain K(+)-channel toxins (KTx), hyaluronidase, proteases and other peptides hitherto identified.