Background. Chemotherapy (CT) may produce growth impairment, however, the pathogenesis is still unclear. Methods. A series of 25 patients mean age 13.3 years (6.3-19.8), previously treated for malignant solid tumours with only CT and surgery were studied. Growth hormone (CH) reserve was assessed by two different provocative stimuli (Clonidine and L-Dopa). Mean time between completion of treatment and GH evaluation was 18.5 months (2-74 months). At that time, all patients were in complete remission. Results. GH deficiency (GHD), defined by an impaired CH response to both provocative tests was observed in 11 out of 25 patients (44%). At diagnosis, mean standing height was +0.23 +/- 1.42 SDS in the CHD group (GHD-g) and +0.18 +/- 1.23 SDS in the non-GHD group (n-GHD-g). At the end of therapy, the mean standing height in the GHD-g was -0.31 +/- 1.22 SDS and -0.17 +/- 1.41 in the n-GHD-g, differing from the former group (P = 0.05). For a mean follow-up of 30 months from the end of treatment, the mean standing height was -0.48 +/- 1.23 SDS in the GHD-g and -0.24 +/- 1.51 SDS for the n-GHD-g (P = 0.03). Growth rate at the end of treatment was +0.13 +/- 1.54 in the GHD-g and +0.21 +/- 1.75 in the n-GHD-g. For a mean follow-up of 30 months from the end of treatment, the growth rate was different between GHD-g and n-GHD-g (-0.31 +/- 2.72 vs. -0.21 +/- 1.93, P < 0.05). Conclusions. 1) Growth impairment in children treated because of malignant diseases has a multifactorial etiology, but CT-induced GH deficiency is one potential adverse factor. 2) An endocrine follow-up should be introduced in order to detect and treat hormonal deficiencies as early as possible. (C) 1995 Wiley-Liss, Inc.