The binding of textilotoxin and its subunits A, B, C and D to polyclonal rabbit antisera directed against textilotoxin, Australian common brown snake (Pseudonaja textilis) and tiger snake (Notechis scutatus scutatus) venoms was studied by ELISA. Subunit D showed greatest reactivity with antisera to textilotoxin and brown snake venom. The phospholipase A2 active subunit A reacted more strongly with antisera to tiger snake venom in keeping with the high degree of homology between the amino acid sequences of subunit A and notexin from tiger snake venom. Subunit A was the only subunit lethal to mice, but at doses 1000-fold greater than for textilotoxin.