Linear alkylbenzene sulphonate (LAS), an anionic surfactant, is the most widely used active component in most of the laundry and cleansing (L& C) compounds. Improper and untreated discharges of domestic and industrial efuents, which largely contain adequate amount of LAS, frequently pollute both lentic and lotic aquatic habitats and adversely affect their ecological prole. Both aquatic ora and fauna are concomitantly exposed to xenobiotic stress on account of surfactants which have registered a spurt both in their production and consumption, globally. Fishes are the worst sufferer of detergent pollution as they lie on top of trophic level in an aquatic food chain. Blood values of shes are sensitive indicators of aquatic pollution as is evident by haematological anomalies in the sh Heteropneustes fossilis exposed to sub-lethal fractions, 1/2, 1/3, 1/4 of 96 h LC of LAS along with its 96 h LC .In present studies, haemoglobin (Hb) and absolute 50 50 erythrocyte count (AEC)were recorded with a decreasing while total leukocyte count (TLC) with an increasing trend in a concentration dependent manner in all exposure groups as compared to unexposed control group. The alterations in the above haematological parameters of the sh can, thus, be used as sensitive indicators of contamination of aquatic regimes on account of LAS.