We examine the relationship between educational inputs—primarily pupilteacher ratios—and school outcomes in South Africa immediately before the end of apartheid government. Black households were severely limited in their residential choice under apartheid and attended schools for which funding decisions were made centrally, by White-controlled entities over which they had no control. The allocations resulted in marked disparities in average class sizes. Controlling for household background variables, we find strong and significant effects of pupilteacher ratios on enrollment, on educational achievement, and on test scores for numeracy.