The processes for acquiring medical records from healthcare facilities in longitudinal cohort studies have not been well examined post-HIPAA Privacy Rule. We examined the response rates, correlates of response rates, and response times for obtaining patient medical records from healthcare facilities under the HIPAA Privacy Rule. Medical records were requested from facilities across the country on adults 45 or older enrolled in the national longitudinal cohort study REGARDS (Reasons for Geographic and Racial Differences in Stroke) who reported physician encounters for potential stroke events. From October 2003 to October 2006, 1,439 medical records were received out of 1,518 reported eligible events (94.7%), with 39 (2.6%) requests pending at the time of the analysis. The refusal rate for record requests from healthcare facilities was only 0.4%. The median length of time to receipt of a record was 26 days (range 1-679 days). Hospitals had the fastest return time (22 days from date of request to date of receipt) compared with outpatient clinics (28 days), doctor's offices (31 days), and long-term care facilities (55 days, p < 0.01). Healthcare facilities located in the Southern region had fastest return time compared with those in the Northwestern region (23 vs. 46 days, p = 0.048). Medical records retrieval in prospective research studies is still feasible under HIPAA regulation. Copyright © 2007 S. Karger AG.