The chromosome complement of the fish cell line AS, derived from the Atlantic salmon (Salmo salar L., 2N = 58), was investigated by C-, Ag-NOR, restriction endonuclease, and BrdU-replication banding. The cell line has a modal chromosome number of 52 with a fixed number of chromosomal rearrangements. The variety of banding patterns obtained allowed us to identify three chromosome markers in the cell line. The identification of their possible origin and significance in karyotype evolution are discussed.