Face-to-face interviews constitute a social interaction between interviewer and respondent, and in the African context, social interactions are strongly shaped by ethnicity. Yet research using African survey data typically fails to account for the effect of shared ethnicity on survey responses. We find that respondents give systematically different answers to coethnic and noncoethnic interviewers across surveys in 14 African countries, but with significant variation in the degree of bias across question types and types of noncoethnic dyads, with the largest effects occurring where both the respondent and interviewer are members of ethnic groups with a history of political competition and conflict, and where the respondent or interviewer shares an ethnicity with the head of state. Our findings have practical implications for consumers of African survey data and underscore the context dependence of the social interaction that constitutes the survey experience.