Fifteen years of undergraduate medical education curriculum reform at Saga Medical School was evaluated by measuring medical students’ communication and interpersonal skills with a patient satisfaction questionnaire developed by the American Board of Internal Medicine. A multiphase cross-sectional study was conducted at the General Medicine Clinic of Saga Medical School Hospital in phase I (1998–1999), phase II (2001–2002), and phase III (2009–2010). A total of 1,963 patient ratings for 437 medical students’ performance was analyzed. The average scores of phases II and III were significantly higher than for phase I. The average score of female students showed a significant difference between phases I and II, but no difference between phases II and III. The average score of male students showed no difference between phases I and II, but significant difference between phases II and III. The phase II curriculum introduced basic clinical skills and examination and improved female students’ performance. The phase III curriculum was effective for male students because it emphasized the clinical skill program more and introduced problem-based learning. Curriculum reform at Saga Medical School is considered to have made good progress in improving students’ clinical competence and patient-centered attitudes.