This paper finds that, in contexts where female genital cutting (FGC) improves marriage outcomes, this practice curbs girls’ education. We use across ethnic group variation in exposure to a law that banned the practice of FGC in Senegal to investigate whether education and FGC work as substitutes in the marriage market, and to estimate the causal effect of FGC on girls’ education. We find that the ban, which is interpreted as an increase in the cost of FGC, decreased the prevalence of the practice, which later increased educational investments received by girls. The results provide widespread support for the substitution hypothesis and suggest that parental decisions on whether to cut their daughters depend highly on the relative cost of alternative pre-marital investments. On the other hand, the findings dismiss alternative mechanisms to explain why the law raised educational investments such as better health or less adolescent girls leaving school to get married.