ABSTRACTThis article suggests a Gateway Effects theory of discrimination in employment which attempts to link discrimination at the entry port into a job with its effects on later employment experiences and behaviour. A longitudinal sample of black and white 1971 school-leavers from Bradford and Sheffield was used to propose this theory. An attempt is made to generate a theory about discrimination which explains the position of black British school-leavers and which also incorporates the concerns of existing alternative American-based labour market theories about discrimination. Several implications for policies about discrimination are deduced.