This study examined new nurses’ mental health based on their interpersonal relationships in the workplace. The authors garnered data through interviews with working nurses who have moved from other hospitals and experienced nurses who have retired,and generated a model using the data. This model indicated that new nurses’ interpersonal stresses are mainly brought about by relationships with older nurses. Specifically,it was demonstrated that new nurses feel strong mental distress when their interactions with older nurses cause negative cycles in their actions and emotions,including maladjustment to the job. Additionally,it was found that the social environment in the workplace is the main factor contributing to these negative cycles.