In this work we were study about the lipid composition of some fresh water fishes collected from Darbhanga locality. Fish is consumed in this Gangetic plain mainly for protein and lipids. Fishes contain unsaturated fatty acids as lipid-component. Accordingly, the study was conducted by selecting two river stretches of Darbhanga District. These included stretches of river Kamala located in village Pokharam and stretches of river Balan located in village Pohaddi. Fish collections was done with bag nets of standardized dimensions with several mesh-sizes. There is selection of Labeo rohita (Rohu), Labeo calbasu and Catla catla a plankton feeder, phytoplankton and detritus feeder respectively in water column. The health clues hidden in fish flesh consumption encountered through popular dailies and reviews (The Times of India, Sunday review, July.18 Aug.8 and Aug.22 and Dec.18, 2001) attracted the present attention on this particular problem. According to fat extraction by Soxhlet extraction method; fat content of Labeo rohita varied between 23-30% while the iodine value was in range of 90-102. The level of triglyceride could be measured between 402-410 mgm (%). The saponification value was recorded between 101-171.2 and acid value between 8.81and 9.21. Whereas, the fat contents of Catla catla was recorded between 24.6-26.7%, Iodine value in the range of 96-97, saponification value between 152.4-158.7 and acid value between 7.8-8.61. These values in L. calbasu were recorded as: fat content 25.6 – 27.1%; Iodine value 96-98; Saponification value 133.4-140.3 and acid value 6.93-7.6. The findings suggest that the total fat content in all the major carps were comparable to each other. The study also suggests that in general the fat content of fish increases during winter season probably on account of availability of quality food. However, with regard to w6 and w3 profile the Labeo rohita and Labeo calbasu the phytoplankton and detritus feeders respectively shows a better range of w3 fatty acids than Catla catla, a zooplankton feeder which appears to be rich in w6 fatty acids.