Background: While longitudinal primary care is thought to promote patient rapport and trust, it is not known if longitudinality helps overcome barriers to communication that may occur when the patient and physician are of different ethnicities and/or sexes. Objective: To examine if longitudinal pediatric care ameliorates disparities in parent disclosure of psychosocial information associated with ethnic and gender discordance between parent and physician. Design: Longitudinal, observational study of parentphysician interaction at early visits and over the course of 1 year. Participants: Parents (90% African American and 10% white mothers or female guardians) and their infant's assigned primary care physician (white first- and second-year pediatric residents). Main Outcome Measure: Parents' psychosocial information giving measured by the Roter Interaction Analysis System. Results: Sex- and race-related barriers to disclosure of psychosocial information were evident early in the parent-physician relationship. At early visits, African American mothers made 26% fewer psychosocial statements than white mothers; this discrepancy was not affected by physician sex. At early visits, white mothers made twice as many psychosocial statements when seeing white female compared with white male physicians. Conclusions: Patient-centeredness is an important factor promoting psychosocial information giving for African American and white mothers, regardless of physician sex. Longitudinal relationships facilitate mothers' disclosure to physicians of a different ethnicity or sex, but only if physicians remain patient-centered.