In the present study, short term (96hrs) toxicity of Surf excel detergent to two freshwater teleost fishes Catla catla and Labeo rohita has been investigated using static bioassay. The fingerlings of Catla and Rohu were exposed to five different concentrations (10, 12, 14, 16 and 18ppm) of Surf excel for 24, 48, 72 and 96hrs. Data on mortality (%) were analyzed using Grafpad software based on Finney’s Probit statistical method. The 24, 48, 72 and 96 hrs LC50 values of Surf excel to Catla fingerlings were 23.79, 17.87, 15.84 and 14.20 ppm, respectively; whereas for Rohu fingerlings the corresponding values were 17.26, 14.79, 12.74 and 11.06 ppm, respectively. The differences observed in the mortalities of C. catla and L. rohita fingerlings at different concentrations of Surf excel were significant (P < 0.001) and suggestive that mortality could be an important factor of concentration and time of exposure. Of the two organisms tested, the fingerlings of L. rohita were found to be more sensitive than that of C. catla. This study provides further proof for the acute toxicity of detergent pollution on the early stages of economically important freshwater fishes. The results are discussed in the light of available literature.