The comparative toxicities of two petroleum products, petrol and kerosene were examined by exposing Tympanotonus fuscatus to acute concentrations (60, 90, 120 and 150ml/L) of these toxicants for 96 hours. The 48 th hour LC 50 for petrol was 177.36 ml/L, while that of kerosene was 306.16 ml/L. The 96 th hour LC 50 was 34.12 ml/L for petrol as against 111.14 ml/L for kerosene. The 48 th hour LC 50 of petrol was found to be 2.40 x that of the kerosene, while the 96 th hour LC 50 was found to be 3.25 x the value observed in the kerosene. The 48 th and 96 th hour LC 95 for petrol was 317.88 and 99.54 ml/L while that of kerosene was 1079.11 and 433.94 ml/L. The mean lethal time (MLT 50) of petrol in the various concentrations were 61.64, 68.09, 44.71 and 43.17 hours for 60, 90, 120 and 150 ml/L respectively. The MLT 50 of kerosene in the Various concentrations were 90.13, 84.06, 79.02 and 73.27 hours for 60, 90, 120 and 150 ml/L. There was a time and concentration dependent mortality of Tympanotonus fuscatus in both media. The mortality rate in petrol was found to be higher than that of the kerosene in all situations. The results suggests that both petrol and kerosene are toxic to the environment with petrol being more toxic than the kerosene.