Objective: No nationwide reports have focused on patients with decompression illness (DCI) transported by doctor helicopter (DH) in Japan. We performed this retrospective study to examine this population using data from the Japan DH registry system (JDRS).Patients and Methods: Patients were initially selected from the JDRS database. They were divided into two groups: those transported by the Eastern Shizuoka DH (ES-DH) and those transported by other DHs. Variables were compared between the two groups.Results: There were 44 patients who had DCI out of 41,592 patients in the JDRS. The majority of cases (70%) were transported by the ES-DH. In the ES-DH group, age, rate of request type using key words, and rate of instrumental intervention to secure an airway were significantly greater, and the median Glasgow Coma Scale score was significantly lower than that of the other DH group. However, there was no statistically significant difference in the rate of cases with fatal outcomes between the two groups.Conclusions: This is the first report regarding the current status of patients with DCI transported by DH in Japan. Most patients were transported by ES-DH to the Izu Peninsula. In addition, the patients transported by ES-DH due to decompression illness tended to be severely ill; however, the outcomes of the ES-DH and other DH groups did not differ to a statistically significant extent and therefore effective recompression therapy could be successfully performed at suitable hospitals owing to timely transportation.