Pooled venom of peninsula tiger snakes (Notechis ater niger) from 11 insular populations and one mainland area, and from a single population of the mainland tiger snake (N. scutatus) were subjected to SDS-PAGE and gel filtration chromatography. At least 20 proteins were resolved in the SDS-PAGE, some of which were common to all populations, but many others were highly variable. Elution profiles produced through gel filtration showed a clustering of some populations with like profiles, while others had distinctive patterns. Similarities and dissimilarities between each population venom profile were appraised. Variation in the venom patterns was independent of prey type or local ecology. Statistical analysis of the SDS-PAGE banding patterns suggests that grouping of populations was dependent on their relative geographic position and the time of isolation of each population from one another and the mainland population.