Open AccessOut of various environmental factors that influence aquatic organisms, temperature is the most all-pervasive. The environmental temperature also affects blood vascular system of aquatic organisms. The present paper deals with the effect of temperature on the Erythrocyte Sedimentation Rate of freshwater fish, Channa punctatus. The freshwater fish, Channa punctatus, were collected from Godavari River, Nanded (Maharashtra). They were acclimated to laboratory condition. The fishes were exposed to different temperatures viz. 15°, 20°, 25°, 30°, 35° and 40° C. The sedimentation rate depends on the RBC count variations. The Erythrocyte Sedimentation Rate was observed at different temperature stress. The values were compared with the fish’s acclimated to ambient temperature. The Erythrocyte Sedimentation Rate was found to be increased when Channa punctatus acclimated to cold temperature stress. The sedimentation of erythrocytes was found to be decreased at warm temperature stress.