Mortality of sea snakes due to commercial trawling along the Goa coast was studied from November 2002 to April 2003. Fishing trawlers from four fishing bases were accompanied to collect data on sea snakes caught as bycatch. Species composition and distribution of sexes at different depths were examined. Magnitude of mortality, which was the number of dead sea snakes and ‘intensity’, which was the proportion of dead sea snakes in a trawl were compared across different class intervals of duration and depth of trawl. Bruises were recorded in different parts of the snake’s body to identify the causes of mortality. The diet of sea snakes was identified and compared with commercially exploited fish taxa. Four species of sea snakes Lapemis curtus, Enhydrina schistosa, Thallasophina viperina and Acrochordus granulatus were represented in a catch of 1.28 × 10-5 sea snakes per net hr in 194 trawls. The catch per unit effort varied significantly across the sites. The composition of sea snake species in the catch varied with depth. The sexes in L. curtus were evenly represented in all the depth classes. The mortality of sea snakes was correlated with the number of individuals caught (r = 0.881). Magnitude and intensity of mortality increased with trawl duration and depth. L. curtus was more susceptible to mortality due to trawling than E. schistosa. Sea Snake mortality was also influenced by the time of the day, season and number of bruises they succumb to during trawling. Majority of the sea snakes prey was also commercially important. Intense harvesting, if continued will impact sea snake populations through mortality and depletion of prey base.