A group of 17 endocrinologically normal short stature adolescent (9 females aged 11.8 +/- 1.5 years and 8 males aged 13.2 +/- 1.1 years) referred at a pubertal stage II-III according to Tanner with a height prediction below -2.5 SD according to Bayley and Pinneau, were treated with long-acting D-Trp6-luteinizing hormone-releasing hormone (3.75 mg i.m. monthly for 24 months) and observed for a period of 13.4 +/- 5.8 months. Pubertal progression was suppressed during the 2 years of analogue therapy, then resumed shortly after the end of treatment. Annual growth rate remained in the prepubertal range during the treatment period and did not increase with the resumption of sexual development. A reduced rate of bone maturation was observed during the 2 years of analogue treatment without clear-cut improvement of the height to bone age relationship at the end of the treatment nor after the post-treatment observation period. Thus, after approximately 3 years of study, no significant improvement of predicted adult stature was obtained. There were no side-effects, but psychological problems mainly related to the failure to increase height. Though methods for predicting adult height are not accurate, these data suggest that use of luteinizing hormone-releasing hormone analogue in endocrinologically normal short subjects entering puberty at normal age with a poor height prognosis does not offer enough possible advantages on growth to offset the possible psychological drawbacks, and cannot be considered as routine treatment in this situation.