Heavy Metals are one of the most important toxicant which destroys the aquatic ecosystem. Their natural effects are carcinogenic and mutagenic. The present study showed the concentration of heavy metals (Fe, Cu, Zn and Pd) in the ovary of Liza parsia from two sites of Ashtamudi lake, the Ramsar site. The heavy metals are found to be accumulated more in the site 2 than in site1. The study also demonstrates the histological changes associated with the accumulation of toxic heavy metals in the ovary thereby its reproductive potential. The histological changes in the ovary of the L. parsia include enlargement of oocytes, degeneration of egg envelope, appearance of atretic follicles, scattering of nucleoi etc.