We evaluated the final height achieved by 47 patients who had bone marrow transplantation (BMT) for thalassemia major. Subjects were separated into two groups: patients who received BMT before 7 years of age and patients who received BMT after 7 years of age. Parental height and genetic target height (TH) were calculated. Our data indicated a strict correlation between age at time of transplant and final adult height. The patients whose age at transplant was <7 years had a less impaired growth rate than did patients who were >7 years. Moreover, greatest loss in height was observed in subjects who had higher serum levels of transaminase and ferritin and these biochemical parameters were strictly correlated to the final adult height. Mean final adult height, however, did not differ from the genetic target height in subjects who received BMT before 7 years of age and the final height SDS corrected for TH surpasses even the TH. In contrast, the subjects who received BMT after 7 years of age, failed to achieve their full genetic potential. In conclusion, short stature is present in a significant percentage of transplanted thalassemic children. The data in this study indicate a close effect of the age at time of transplant on subsequent growth rate, but the growth impairment in these subjects remain multifactorial.