The diet of chinook salmon in New Zealand coastal waters is described, based on 803 adult salmon taken by commercial bottom trawlers in depths of 40–70 m off the mid‐Canterbury coast during three summers from 1991/92 to 1993/94, and 36 yearlings caught in a shallow coastal embayment in 1992 and 1993. Adult chinook salmon were primarily piscivorous, stout sprat—Sprattus muelleri—comprising 76% of the diet by weight. Pelagic swarming postlarval juveniles of the galatheid crabMunida gregaria, known as red krill, and juvenile hoki,Macruronus novaezelandiae, comprised 18% and 5% of the diet, respectively. Prey diversity was extremely low, both in terms of the number of species consumed (10), and the proportion of stomachs containing a single prey type (81%). Diet showed no relationship to predator size or geographical area. Interannual variabilityof Munidaand hoki in the diet appeared to be related to changes in their abundance. Diet of yearling salmon consisted of several larval fish species and the mysidTenagomysis macropsis. Both adult and yearling chinook salmon appeared to feed opportunistically on a relatively narrow spectrum of pelagic prey close to the ocean floor.