Background: Recombinant human growth hormone (rhGH) is being used to promote linear growth in short children with Noonan syndrome. However, its efficacy is still controversial. Aims: To systematically determine the impact of rhGH therapy on adult height in children with Noonan syndrome. Methods: We searched the Cochrane Central Register of Controlled Trials, ISI Web of Science, MEDLINE, and the bibliographic references from all retrieved articles published until April 2014. Studies reporting adult/near-adult height in children with Noonan syndrome treated with rhGH or reporting at least a 3-year follow-up were analysed. Quality and strength of recommendation were assessed according to the Endocrine Society criteria. Results: No controlled trials reporting adult height were available. Five studies were identified reporting adult height or near adult height. Data comparison showed inter-individual variability in the response to rhGH, mean height gain standard deviation score ranging between 0.6 and 1.4 according to national standards, and between 0.6 and 2 according to Noonan standards. Significant biases affected all the studies. Conclusions: High-quality controlled trials on the impact of rhGH therapy on adult height are lacking, and the robustness of available data is not sufficient to recommend such therapy in children with Noonan syndrome.