Tityus serrulatus is considered the most dangerous scorpion in Brazil. It is widely distributed, especially in the Southeast region, and is responsible for the highest number and most severe accidents. This chapter focuses on Tityus serrulatus scorpion venom (Tsv) and aspires to unravel its complex composition with emphases on its isolated proteins, their targets, structures, and functions. It takes a closer look at the peptides related to the Na + and K + channel toxin families, NaTx and KTx, respectively, including their toxin precursors. Additionally, a hyaluronidase, a serine proteinase, metalloproteinases, and many other proteins/peptides, such as a nontoxic protein (Ts4), PAPE peptides, bradykinin-potentiating peptides (BPP), antimicrobial peptides (AMP), anionic peptides, and venom peptides with undetermined functions, were reported.