There is a lack of understanding of what may drive gender disparities in healthcare utilization and outcomes. We present novel evidence on the impact of physician-patient gender match on healthcare quality using standardized patients (SPs) in an experiment, and collected interactions between SPs and physicians in a primary care setting. We find that, compared with female physicians treating female SPs, female physicians treating male SPs had a 23.4 pp increase in correct diagnosis and a 19.0 pp increase in correct drug prescriptions. Despite substantial gains in healthcare quality, there was no significant rise in medical costs or time investment. The gains in care quality were partly attributed to better physician-patient communications, not the presence of more clinical information. More importantly, female physicians treating male SPs prescribed more unnecessary tests but fewer unnecessary drugs to balance their time commitment and costs. The results suggest the role of gender norms and physician defensive behavior when female physicians treat male SPs. Our findings imply that improving patient centeredness may lead to significant gains in the quality of healthcare with modest costs, while reducing gender gaps in care quality.