The use of captive broodstocks for endangered and threatened Pacific salmon populations is being investigated and used as a possible stock recovery tool. Among the options for initiating a captive broodstock project is the choice of rearing environment. The purpose of this project was to compare and analyze the effects of freshwater and saltwater captive broodstock rearing on reproductive performance of chinook salmon. Specifically, the project objectives were to quantify effects of freshwater versus saltwater rearing, family effects and interactions between family and environment on adult-size measures, egg quantity and fertility, and fry development success. Sea pen-reared broodstock had larger males, and the progeny of the sea pen-reared females had higher developmental mortality, most of which was due to egg fertility. Families differed from each other significantly in female size, egg infertility, and mortality from eye to hatch. Total developmental mortality from green eggs through yolk absorption was greater for eggs from the sea pen-reared females and was highly correlated with egg infertility. Overall, the major goal of analysis of variance based on the matrix of experimental crosses was not achieved because of low survival and maturity rates of sea pen-reared broodstock, especially in males. However, efforts were made to complete the crosses, and while the original crosses were not completed, satisfactory analyses were possible because of crosses made between females from the target families and males from other, nontargeted families.