This study was carried out between January 2010 and December 2010 to determine the parasites and their effect on growth of carp (Cyprinus carpio L., 1758) inhabiting Karacaoren II Dam Lake. Sixty four samples were captured on monthly basis, their age and parasites were examined. These fish fall in groups I-VIII and 39 (60.9%) of them harboured Dactylogyrus anchoratus, Dactylogyrus minutus, Argulus foliaceus, Lernaea cyprinacea, Caryophyllaeus laticeps and. Bothriocephalus acheilognathi. It was determined that among the fish of same sex and age and captured during the same month, the ones without a parasite were longer and heavier than the ones with parasite. It was found that the parasitized carps were shorter and weaker than the ones without a parasite.