Microcytic-hypochromic anaemia was induced in Oreochromis niloticus (Trewavas, 1983) at intervals of 1, 14 and 28 days. Experimental fish were exposed to test water separately diluted with sub lethal concentrations of sniper 1000EC of 0, 0.12, 0.15, 0.19and 0.25mg/L. Experimental design was a complete randomized design. A 28 day exposure to sub lethal concentrations of the toxicant resulted in microcytic-hypochromic anaemia in the exposed fish on days (1, 14 and 28). Blood dyscrasias attributable to microcytic- hypochromic anaemia was observed with a significant (p<0.05) decrease in haemoglobin, haematocrit, red blood cells, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC). White blood cells, lymphocytes, monocytes, Neutrophils, eosinophil and basophil increased significantly (p<0.05) with increasing concentrations of the toxicant. It was concluded that sniper 1000EC induced microcytic-hypochromic anaemia in the exposed fish.