The literature contains a substantial amount of information about factors that adversely influence the linear growth in up to 85% of patients undergoing haematopoietic SCT (HSCT) with TBI and/or cranial irradiation (CI) for acute leukaemia (AL). By contrast, only a few studies have evaluated the impact of growth hormone (GH) therapy on growth rate and final height (FH) in these children. We evaluated growth rates during the pre- and post-transplant periods to FH in a group of 25 children treated with HSCT (n=22), TBI (n=21) or/and CI (n=8) for AL and receiving GH therapy. At the start of GH treatment, the median height Z-score was -2.19 (-3.95 to 0.02), significantly lower than at AL diagnosis (P<0.001). Overall height gain from start of GH treatment to FH was 0.59Z (-2.72 to 2.93) with a median height Z-score at FH of -1.35 (-5.35 to 0.27). This overall height gain effect was greater in girls than in boys (P=0.04). The number of children with heights in the reference population range was greater after than before GH therapy (P=0.07). At FH the GVHD and GH treatments lasting <2 years were associated with shorter FH (P=0.02 and 0.05). We found a measurable beneficial effect of GH treatment on growth up to FH.