The aim of present study was to survey the fatty acid composition and fat content in common carp (Cyprinus carpio L.) fillet captured in five different fish farms located in Hungary. Lipid peroxidation characteristics (conjugated dienes and malondialdehyde levels) were also determined in fish muscle. Data on fatty acid composition of common carp has shown that different methods of rearing and feeding cause significant differences in the proportions of n-6 and n-3 polyunsaturated fatty acids of this fish species. According to present results, it seems that the feeding practice of the last month before capture has determined the fatty acid profile of fillet, therefore the technology of carp nutrition should be divided into two main periods: first a growth and weight gain period; and a second one when the nutritional quality of the fillet composition can be improved.