Pubertal development was retrospectively evaluated in 58 children with cancer, mostly acute lymphoblastic leukemia (ALL), who are in complete remission and off chemotherapy. Six girls [5 patients with ALL, and 1 with malignant lymphoma (NHL)] showed advanced puberty (25.0%, 6 of 24 female patients with ALL and NHL) through the evaluation of their growth velocity. No evidence for advanced puberty was seen in the males. All 6 girls had received cranial irradiation for central nervous system prophylaxis and systemic chemotherapy including glucocorticoid. The mean age at onset of the pubertal growth spurt in these 6 girls was significantly lower than for girls with a solid tumor [6.90 ± 0.10 and 9.00 ± 0.77 (mean ± SD) years, respectively (p < 0.001)]. By simply evaluating the height velocity, we could predict advanced puberty which was ultimately associated with short stature.