BACKGROUND. Because of treatment-related toxicity, research is increasingly being focused on long-term sequelae secondary to hematopoietic stem cell transplantation (HSCT) in survivor populations. METHODS. This study describes the incidence of auditory, sensory, motor, and visual impairments, including cataracts, among 235 individuals who were treated with HSCT during childhood or adolescence. Outcomes were compared with 705 siblings of childhood cancer survivors. Participants completed a survey with questions on posttransplant organ system impairments. Approximately half of survivors were transplanted when younger than 10 years of age. The median length of followup was 11 years. RESULTS. The cumulative incidence of cataracts was 36% at 15 years post-HSCT, although cataracts occurred only in those who received total body irradiation as an HSCT conditioning agent or head irradiation before transplant. Persistent pain was reported by 21% of survivors. Loss of hearing in one or both ears, and legal blindness in one or both eyes, each occurred after transplant in 2% of survivors. Occurrences were uncommon, but survivors were 4.3 times (95% confidence interval [CI]: 2.0-9.4) more likely to report coordination problems, 7.7 times (95% CI: 3.2-18.5) more likely to report chewing or swallowing problems, and 3.5 times (3.5; 95% CI: 1.6-7.9) more likely to report muscle weakness than those in the comparison group. Muscle weakness was strongly associated with positive history of chronic graft-versus-host disease. CONCLUSIONS. Increased risks were found for motor impairments, hearing loss, vision loss, and persistent pain among study participants. Cataracts were a frequent adverse effect, suggesting that close monitoring with appropriate intervention for preservation of vision, particularly among those who received total body irradiation, should be a primary goal in survivors of HSCT performed in childhood. © 2006 American Cancer Society.