This article analyzes the role of fertility surveyors as framing specialists, who in the 1940s portrayed Latin American populations as likely to change their attitudes regarding birth control. A heterogeneous group of social scientists, clinical workers, and their financial supporters, all of whom were interested in population limitation and women’s health issues, were involved in the deployment of the fertility survey, a tool that played an essential role justifying the promotion of birth control methods and population limitation policies. This group also included locals who became involved in research alongside US experts, albeit as unequal partners.