We report a pilot study of a home-based aerobic exercise program in a group of 17 adult hematopoietic stem cell transplant (HSCT) recipients. Participants had received no cancer treatment for at least 6 months and reported leisure time physical activity less than 20 min per day and fewer than three times a week during the previous month. Following baseline assessments of aerobic fitness, fatigue symptoms, and quality of life, participants were placed on home-based aerobic exercise programs consisting of 20-40 min of activity in the target heart rate zone (40-60% predicted heart rate reserve) delivered in three to five sessions per week for 12 weeks. Subjects were supplied with electronic heart rate monitors and we encouraged program adherence using weekly telephone contacts and exercise diaries. In all, 32 of the 42 qualified candidates consented (acceptance=76%). Of these, 17 kept appointments for baseline assessments, four did not complete the study (attrition=46%), and no exercise-related adverse events were reported. Scores on measures of aerobic fitness, fatigue severity, and physical well-being improved (signed ranks test; P<0.05) during program participation. Our findings suggest that individually prescribed, home-based aerobic exercise is an acceptable, safe, and potentially effective intervention for improving physical functioning and fatigue in sedentary HSCT recipients.