Growth and sexual development were evaluated in 54 (29 female, 25 male) patients with beta-thalassemia major aged 2.7-21.3 years (mean 10.4 yr). Mean pretransfusion hemoglobin concentration was 7.8 +/- 0.7 mg/dl. All patients except 6 were on desferrioxamine. Age of starting of therapy was 6.8 +/- 3.9 years, Mean SDS values for height, weight and sitting height were significantly lower (p<0.001) than control cases of similar age, Height deficiency exceeded -2 SD in 18 patients and a delay in bone age (>2 SD below the mean) was observed in 36 out of 54 patients. Among 11 patients over 14 years, 9 showed delay in onset or progression of puberty and 10 had growth retardation. Height SDS were negatively correlated with chronological age, age of onset of desferrioxamine and present serum ferritin levels (p<0.001). These findings indicate that abnormal growth and delayed puberty are frequent in transfusion dependent thalassemics. These can be partly overcome by early onset of chelating therapy.