OBJECTIVES: In many countries, minority ethnic groups report poorer care in patient surveys. This could be because they get worse care or because they respond differently to such surveys. We conducted an experiment to determine whether South Asian people in England rate simulated GP consultations the same or differently from White British people. If these groups rate consultations similarly when viewing identical simulated consultations, it would be more likely that the lower scores reported by minority ethnic groups in real surveys reflect real differences in quality of care. DESIGN: Experimental vignette study. Trained fieldworkers completed computer-assisted personal interviews during which participants rated 3 video recordings of simulated GP-patient consultations, using 5 communication items from the English GP Patient Survey. Consultations were shown in a random order, selected from a pool of 16. SETTING: Geographically confined areas of ∼130 households (output areas) in England, selected using proportional systematic sampling. PARTICIPANTS: 564 White British and 564 Pakistani adults recruited using an in-home face-to-face approach. MAIN OUTCOME MEASURE: Mean differences in communication score (on a scale of 0-100) between White British and Pakistani participants, estimated from linear regression. RESULTS: Pakistani participants, on average, scored consultations 9.8 points higher than White British participants (95% CI 8.0 to 11.7, p<0.001) when viewing the same consultations. When adjusted for age, gender, deprivation, self-rated health and video, the difference increased to 11.0 points (95% CI 8.5 to 13.6, p<0.001). The largest differences were seen when participants were older (>55) and where communication was scripted to be poor. CONCLUSIONS: Substantial differences in ratings were found between groups, with Pakistani respondents giving higher scores than White British respondents to videos showing the same care. Our findings suggest that the lower scores reported by Pakistani patients in national surveys represent genuinely worse experiences of communication compared to the White British majority.