This study aims to investigate the effectiveness of flipped learning in surgical education in trauma. The participants were 15 first-year general surgery residents in Shiraz medical school. After completing a pre-test, the participants received the learning content in interactive multimedia, podcasts, movies, and books. One month later, they had a face-to-face class based on case-based discussions. An early post-test was performed immediately after the class, and a late post-test was performed one month later. In these tests, the residents' problem-solving abilities were assessed using multiple-choice questions. A semi-structured phone interview was used to measure their attitude towards the learning program. The results showed a significant difference between pre-test and early post-test scores and between pre-test and late post-test scores. However, there was no significant difference between early and late post-test scores. The residents were satisfied with the program's overall usefulness for junior residents. The participants tended to use podcasts more than other materials. They mentioned that the videos and books helped more to foster theoretical knowledge. The case-based discussion makes them more confident in dealing with patients in daily encounters.