This prospective longitudinal study examined the quality of life (QOL) after hematopoietic cell transplantation (HCT) and identified risk factors of poor QOL in 312 adult autologous and allogeneic HCT patients. Physical, psychological, social, and spiritual well-being was assessed before HCT, 6 months, and 1, 2, and 3 years after HCT. For all HCT patients, physical QOL was stable from before to after HCT (P > .05); psychologic (P < .001), social (P < .001), and spiritual (P = .03) QOL improved at 6 months. Study noncompleters (because of illness or death) had worse QOL. Allogeneic patients reported worse physical and psychologic well-being (P < .05). Older patients reported worse physical but better social well-being regardless of HCT type (P < .05). Two or more domains were affected by race/ethnicity, household income, and education in autologous patients, and by body mass index (BMI), decline in BMI, primary diagnosis, and chronic graft-versus-host disease (GVHD) in allogeneic patients (P < .05). At 3 years, 74% of HCT patients were employed full or part time. Older autologous patients with lower pre-HCT income were less likely to work (P < .05); allogeneic patients with chronic GVHD were less likely to work (P = .002). Multidisciplinary efforts to identify and support vulnerable subgroups after HCT need to be developed.