This paper explores the adequacy of several theories advanced to account for the sexual division of labour – neoclassical, dual labour market, marxist feminist, and technologically determined – by comparing the historical processes by which the gender segregation developed in the hosiery and knit goods industry in Canada and Britain in the period 1890 to 1950. It argues that the sexual division of labor is formed within the shifting mutuality and antipathy of gender relations and the relations of production so that theories of sexual segregation must integrate rather than isolate class and gender based processes.