Abstract: Present study was designed to investigate any seasonal (spring, summer, monsoon, autumn and winter) fluctuations in haematological parameters in the blood of Tor putitora. Significant seasonal variations in the number of white and red blood cells, haemoglobin, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration have been observed. In general, higher values of RBC dependent parameters ;viz, TEC, Hb, PCV were recorded during spring, summer, monsoon and autumn, and lowest during winter. White blood cells on other hand, exhibited gradual decline during monsoon and autumn upto winter only to rise again in spring and summer. The proportions of different leucocytes though variable but lymphocytes have been observed to be the chief contributor in TLC fluctuation. Thrombocyte count was significantly higher during autumn and winter season. Relation between seasonal changes in environmental factors such as temperature and dissolved oxygen with various blood parameters have been discussed.