The concentrations of selected Organochlorine (OC) pesticides (α-HCH, β-HCH, γ-HCH, HCB, aldrin, 2,4'-DDE, 4,4'-DDE, 2,4'-DDT, 4,4'-DDT) and Polychlorinated Biphenyls (PCBs) (28, 70, 74, 81, 99, 101, 105, 118, 128, 138, 153, 156, 170, 180, 183, 187) were measured in two species of cultured freshwater fish (rainbow trout, Oncornhychus mykiss and catfish, Silurus glanis) and two kinds of sea fish (mullet, Mugil cephalus and salmon, Salmo salar) between March 2008 and June 2009 in order to evaluate the status, seasonal changes and potential sources of pollution in the Samsun region of Turkey. Concentrations of total PCBs ranged from 17.6 to 335 ng/g in rainbow trout, 1,063 to 3,234 ng/g in mullet, 21 to 1,887 ng/g in salmon and 108 to 1,172 ng/g lipid in catfish and total OC pesticide concentrations ranged from 303 to 473, 319 to 6,158, 101 to 249 and 34 to 6,069 ng/g lipid in rainbow trout, mullet, salmon and catfish, respectively. It is concluded that the levels of persistent organic pollutants should be monitored regularly and rigorously by the appropriate government agency, with mandatory public reporting.