OBJECTIVES Previous studies have found that the inclusion of medical humanities in medical education was associated with improvements in learner reflectivity and empathy. There is less data, however, on the impact of medical humanities on perceived patient care and mediators of learner outcomes. Our study aimed to determine the impact of medical humanities on perceived learner well-being and patient care, and the mediators of these outcomes in medical undergraduates undergoing psychiatric training. METHODS This cross-sectional study was conducted from August 2021 to December 2022 within undergraduate medical students undergoing psychiatry rotations and who attended sessions entitled “Humanities in Psychiatry.” Both quantitative and qualitative data were obtained through anonymized online feedback forms. Path analysis was performed to examine the relationship between learners’ perception of the medical humanities writing activity and its potential to improve their well-being, patient care, as well as mediators of these outcomes. RESULTS Overall, 97 medical undergraduates (response rate 67.4%) participated in the study and more than four-fifths reported improvements in listening, reflection, empathy, personal well-being, and perceived patient care. Males showed more interest in additional medical humanities sessions (mean rank 57.9 vs 42.5, P = .005) and greater improvements in personal well-being (mean rank 55.1 vs 44.5, P = .044). Path analysis showed that reflective capacity of learners mediated the relationship between reflective writing and perceived improvements in learner well-being (β = 0.596, 95% CI = 0.409-0.737) and patient care (β = 0.557, 95% CI = 0.379-0.702). CONCLUSIONS Our study found that the majority of learners responded positively to the medical humanities sessions, which suggests that its use could be beneficial in fostering empathy, reflection, learner well-being, and improved patient care. Using the PRISM model, we present practical implications for educators to consider when using medical humanities in relation to psychiatry training.