Background: Doctor review websites have become increasingly popular as a source of information for patients looking to selecta primary care provider. Zocdoc is one such platform that allows patients to not only rate and review their experiences withdoctors but also directly schedule appointments. This study examines how several physician characteristics including gender,age, race, languages spoken in a physician's office, education, and facial attractiveness impact the average numerical rating ofprimary care doctors on Zocdoc. Objective: The aim of this study was to investigate the association between physician characteristics and patient satisfactionratings on Zocdoc. Methods: A data set of 1455 primary care doctor profiles across 30 cities was scraped from Zocdoc. The profiles containedinformation on the physician's gender, education, and languages spoken in their office. Age, facial attractiveness, and race wereimputed from profile pictures using commercial facial analysis software. Each doctor profile listed an average overall satisfactionrating, bedside manner rating, and wait time rating from verified patients. Descriptive statistics, the Wilcoxon rank sum test, andmultivariate logistic regression were used to analyze the data. Results: The average overall rating on Zocdoc was highly positive, with older age, lower facial attractiveness, foreign degrees,allopathic degrees, and speaking more languages negatively associated with the average rating. However, the effect sizes of thesefactors were relatively small. For example, graduates of Latin American medical schools had a mean overall rating of 4.63compared to a 4.77 rating for US graduates (P<.001), a difference roughly equivalent to a 2.8% decrease in appointments. Onmultivariate analysis, being Asian and having a doctor of osteopathic medicine degree were positively associated with higheroverall ratings, while attending a South Asian medical school and speaking more European and Middle Eastern languages in theoffice were negatively associated with higher overall ratings. Conclusions: Overall, the findings suggest that age, facial attractiveness, education, and multilingualism do have some impacton web-based doctor reviews, but the numerical effect is small. Notably, bias may play out in many forms. For example, aphysician's appearance or accent may impact a patient's trust, confidence, or satisfaction with their physician, which could in turninfluence their take-up of preventative services and lead to either better or worse health outcomes. The study highlights the needfor further research in how physician characteristics influence patient ratings of care