This study investigated hospitals' attempt at developing retention management for medical staff following large-scale disasters. The impacts of five experiences, i.e., "miserable experiences," "guilt," "workplace changes," "household changes," and "changes in occupational feelings" on medical staff and its impact on their decision to quit was investigated. The survey was conducted via the Internet with doctors and nurses working at hospitals from five prefectures in eastern Japan during the Great East Japan Earthquake. Respondents included 62 participants (31 doctors and 31 nurses). Differences in mean scores, correlational and regression analyses were performed for each experience data obtained. Results revealed a considerable difference between doctors and nurses regarding their misery. Nurses, especially, were susceptible to stress due to miserable experiences following disasters. Hence, mental care was effective in preventing nurses from quitting. Furthermore, the enhanced effects for midterm and long-term retention management were effective measures against household changes and occupational feelings.