We examined genetic variation in mortality, mean time to death, and (for chinook salmon) weight for one population each of chinook salmonOncorhynchus tshawytscha, coho salmonO. kisutch, and chum salmonO. ketain British Columbia. In each of the three populations examined, 15 males were mated to 30 females in a nested breeding design. The progeny from each family were divided into groups, and each group was challenged with one of four pathogens:Vibrio anguillarumorV. ordalii, both of which cause vibriosis;Aeromonas salmonicida, which causes furunculosis; andRenibacterium salmoninarum, which causes bacterial kidney disease. When all three salmon species were considered as a group, heritabilities of mortality (sire component, binary character) were low – less than 0.15 for the Vibrio species andA. salmonicidachallenges, and less than 0.05 for theR. salmoninarumchallenge. Heritabilities of time to death were also low. Family mortality rates in theVibriospecies andA. salmonicidachallenges tended to be positively correlated, but not as a result of additive genetic variation. Similar results were obtained for family mean time to death. At the end of the experiments there was no consistent genetic correlation between family weight and observed mortality rates or time to death. Our results suggest that greater improvements in disease resistance for salmon in the aquaculture industry in British Columbia can be made by judicious selection for the strain or population for brood stock rather than by selective breeding for increased resistance.