The study aims at evaluating, in a causal way, whether health providers in Peru might be contributing to ethnic health disparities in the provision of family planning services. We perform a field experiment that combines audit studies and simulated patient methodologies. The study population consists of clinics in Metropolitan Lima that are administered by the Ministry of Health and which provide family planning counseling services. The sample in our study includes 351 clinics. The primary outcome measured in the study was a composite of service provider compliance to guideline technical tasks in family planning counseling. We pre-defined indigenous and mestizo profiles using distinctive cultural attributes such as clothing, styling of hair, posture and patterns of speech. With a 1:1 allocation as per a computer generated randomization schedule, and using permuted blocks of four, clinics were assigned to a sequence of ethnic profiles, either to receive the indigenous then the mestizo profile (sequence 1) or mestizo and then the indigenous profile (sequence 2) in two periods. The trial comprises two treatment periods each of five week's duration. The second treatment period followed the same sequence of visits than the first one to obtain at least a five-week 'wash-out' period to mask the study.