Abstract Organochlorine insecticide residues were determined in eggs of Dalmatian Pelican ( Pelecanus crispus) as well as in eels ( Anguila anguila) (the main pelican prey). Material was collected at wetlands of Amvrakikos Gulf (North-western Greece) for a two-year period, 1992 and 1993. Residues of the organochlorine pesticides, α-BHC, β-BHC, lindane, 2,4′-DDD, 4,4′DDD, 4,4′-DDE and 4,4′-DDT were found in collected pelican eggs and eels. The bioconcentration factors (BCF) of these compounds had very high values in all samples examined. The BCF values of lindane and α-BHC were in lower levels in pelican eggs and eels, as compared with 4,4′-DDE. The biomagnification factor (BMF) for 4,4′-DDD, 4,4′-DDE and 4,4′-DDT had higher values than α-BHC, β-BHC and lindane in pelican eggs.