Background: Quality of life and psychosocial determinants of health, such as health literacy and social support, are associated with increased health care utilization and adverse outcomes in medical populations. However, the effect on surgical health care utilization is less understood. Objective: We sought to examine the effect of patient-reported quality of life and psychosocial determinants of health on unplanned hospital readmissions in a surgical population. Research Design: This is a prospective cohort study using patient interviews at the time of hospital discharge from a Veterans Affairs hospital. Subjects: We include Veterans undergoing elective inpatient general, vascular, or thoracic surgery (August 1, 2015-June 30, 2017). Measures: We assessed unplanned readmission to any medical facility within 30 days of hospital discharge. Results: A total of 736 patients completed the 30-day postoperative follow-up, and 16.3% experienced readmission. Lower patient-reported physical and mental health, inadequate health literacy, and discharge home with help after surgery or to a skilled nursing or rehabilitation facility were associated with an increased incidence of readmission. Classification regression identified the patient-reported Veterans Short Form 12 (SF12) Mental Component Score <31 as the most important psychosocial determinant of readmission after surgery. Conclusions: Mental health concerns, inadequate health literacy, and lower social support after hospital discharge are significant predictors of increased unplanned readmissions after major general, vascular, or thoracic surgery. These elements should be incorporated into routinely collected electronic health record data. Also, discharge plans should accommodate varying levels of health literacy and consider how the patient's mental health and social support needs will affect recovery.