We retrospectively evaluated the growth of 41 children with constitutional growth delay followed till adulthood and never treated with growth-promoting therapies. Final height has been correlated with prepubertal height, genetic target and height prediction calculated in both prepuberty and puberty. All patients showed a significant improvement of their height standard deviation score (HSDS) from prepuberty to adulthood, and the great majority of them achieved a final height above the 3rd percentile. Moreover, we found a good correlation between final height and both genetic target and height prediction, even if the latter overestimated final height in 25% of the patients. In conclusion, our data confirm that constitutional growth delay is a normal variant of growth. Therefore, caution should be paid in considering pharmacological treatment of this condition.