Selection practices in education, such as tracking, may represent a structural obstacle that contributes to the social class achievement gap. We hypothesized that school’s function of selection leads evaluators to reproduce social inequalities in tracking decisions, even when performance is equal. In two studies, participants (students playing the role of teachers, N = 99, or preservice and in-service teachers, N = 70) decided which school track was suitable for a pupil whose socioeconomic status (SES) was manipulated. Although pupils’ achievement was identical, participants considered a lower track more suitable for lower SES than higher SES pupils, and the higher track more suitable for higher SES than lower SES pupils. A third study (N = 160) revealed that when the selection function of school was salient, rather than its educational function, the gap in tracking between social classes was larger. The selection function of tracking appears to encourage evaluators to artificially create social class inequalities.