Introduction: Surgical specialists and residents lack knowledge to adequately manage frail older patients. This study aims to evaluate the effects of an interactive online course regarding attitude, self-confidence and knowledge in perioperative management of the elderly patient. Methods: The six-weeks course consisted of expert videos, literature readings, quizzes and forum discussions. Surgical consultants with geriatric expertise and geriatricians moderated online discussions and stimulated interaction. Knowledge, self-confidence and attitude of course participants were compared at the beginning and end of the course. Results: 206 medical practitioners started the course. Knowledge scores improved significantly from 49% to 65% (p < 0.005). Participants felt more secure (p < 0.005) in the treatment of the older patient at the end of the course. A better attitude correlated with a higher total knowledge score in surgeons and surgical residents (p = 0.02). Conclusion: A six-week interactive online course on perioperative management of elderly patients increases relevant geriatric knowledge and improves self-confidence of residents and faculty.