Patients who undergo hematopoietic SCT (HSCT) often experience physical and psychological problems, even long after treatment has been completed. This study was performed to evaluate the effects of a 12-week outpatient physical exercise (PE) program, incorporating aerobic and strength exercises, as compared with a usual care control condition on patients' physical performance and psychosocial well-being. Patients who had completed HSCT up to 6 months earlier were randomly assigned to a supervised PE program (n=64) or a usual care control group (n=67). Primary outcomes were quantified physical performance and self-reported physical functioning. Secondary outcomes were body composition measurement, quantified walking activity and patient-reported outcomes (physical activity, fatigue and health-related quality of life). Assessments were at baseline, immediately after program completion and at 3-month follow-up. Significant intervention effects were observed at both posttreatment and follow-up on physical performance measures. No other outcomes yielded statistically significant group differences. PE should be considered in the management of HSCT recipients to improve physical performance after discharge from the hospital. Further research is needed to determine how the program can be enhanced so that improved physical performance also translates into improved physical and psychosocial functioning in daily life.