ABSTRACT The present study deals with the heavy metal concentration in soft tissue of freshwater lamellibranch mollusks inhabiting in the Krishna river at Ankali. The bivalve, L. marginalis (Lamarck) was selected in the present study. This species of mollusks was subjected for detection of heavy metals such as Nickel, Zinc, Lead and Aluminium from various soft tissues such as mantle, gill, siphon, foot, hepatopancreas and gonads. The work was carried out seasonally for the period from January 2013 to December 2013 and values were recorded in ppm. Accumulation of Zn was maximum in gills, while minimum in foot in different seasons. Similarly accumulation of Ni, Pb and Al was maximum in gonads whereas, it was minimum in siphon in different seasons Keywords: Heavy metals, Soft organs, L. Marginalis, Krishna River REFERENCES Ayyavoo, M. (1989): studies on the metal concentration on Cauvary River and Poompuhar East-coast Tamil Nadu. National Young Scientist Seminar on Environmental pollution. March 30-31, Page 10 Ganesan, V. C. (1991). Trace metal concentration in water and sediment of the river Khan and Kshipra (Ujjain, India). Inter. J. Ecol. And Environ. Sci. 17: 225-236. Kataria, H. C. (1994): Heavy metals contamination and pollution in Betwa River. JEP, 15 (1): 34-38. Lind, O. T (1974): Hand book of common methods in limnology. The C. V. Mosby Co., Saint Louis (USA). Lithnor, G. (1975): Methods for detection, measurement and monitoring of water pollution, FAO, Rome, PP 41. Mani, S. S., Sweth Aranyam and S. S. Daevi (1989): An increased level of trace metals in Pazhan Cauvery river water due to domestic sewage pollution. Seminar on Environmental pollution, 30 March, Bangalore. Moriarty, F. and H. M. Hanson (1989): Heavy metals in sediments of the river Ecchesbourne, Darbishire. Water resources, 22: 475-480. Trivedy and Goal (1987): Practical methods I Ecology and Environmental Science.