We analyzed allozymes from 13 collections of lingcodOphiodon elongatusrepresenting over 1,100 individuals throughout most of the species' range from Alaska to central California. Data were gathered from 41 presumptive gene loci of which 19 loci (46%) were polymorphic (P0.99criterion, whereby the frequency of the most common allele is 0.99 or less in at least one collection). Average observed heterozygosity was 0.050 (SE, 0.001). Significant differences in genotype frequencies were found between sexes at theAH-2*locus for aconitate hydratase. Although lingcod populations are genetically similar throughout the range, significant allele frequency differences suggest that lingcod in Puget Sound are partially isolated from those along the open coast.