Chromium is one of the most common elements in the earth’s crust and is used in more than 50 different industries. There are three oxidation states in case of Chromium viz., Cr (II), Cr (III), Cr (VI). Among which Cr (II) is most unstable. Cr (III) and Cr (VI) are the stable oxidation state of Chromium in the environment. Being one of the commonly used metals Chromium and its particulates enter the aquatic medium through effluents discharged from different industries like textiles, tanneries, electroplating workshops, ore mining, dyeing, printing-photographic and medical industries. The discharge from these industries pollutes the waters and affects the biota. Chromium is known to cause various health effects. The health hazards associated with exposure to chromium are dependent on its oxidation state. The Hexavalent form is toxic than trivalent form. The hematological alterations produced on exposure to sub-lethal concentration (1/10th of LC50/96 hrs) of chromium were investigated in fresh water fish, Labeo rohita. Labeo rohita common name (Rohu) is a species of fish of the carp family, found in rivers of South Asia. This fish is commonly found in Pakistan, India, Nepal, Bangladesh, Burma, Thailand, China, Kampuchea and Sri Lanka. The rich source of high-quality protein filled with vitamins and omega-3 fatty acids encourage the human being to uptake fish as a major food source. Significant decrease in haematological indices RBC, Hb, PCV, MCH, and MCHC and WBC and MCV values were significantly increased. The decrease in hematological parameters clearly indicates that the exposed fishes have become anemic due to heavy metal exposure.