Objective: To compare response rate, time to response, and data quality of electronic and postal surveys in the setting of postgraduate medical education. Study Design and Setting: A randomized controlled trial in a university-based internal medicine residency program. We randomized 119 residents and 83 faculty to an electronic versus a postal survey with up to two reminders and measured response rate, time to response, and data quality. Results: For residents, the e-survey resulted in a lower response rate than the postal survey (63.3% versus 79.7%; difference -16.3%, 95% confidence interval (95% CI) -32.3% to -0.4%%; P =. 049), but a shorter mean response time, by 3.8 days (95% CI 0.2-7.4; P =. 042). For faculty, the e-survey did not result in a significantly lower response rate than the postal survey (85.4% vs. 81.0%; difference 4.4%, 95% CI -11.7 to 20.5%; P =. 591), but resulted in a shorter average response time, by 8.4 days (95% CI 4.4 to 12.4; P < 0.001). There were no differences in the quality of data or responses to the survey between the two methods. Conclusion: E-surveys were not superior to postal surveys in terms of response rate, but resulted in shorter time to response and equivalent data quality. © 2005 Elsevier Inc. All rights reserved.