Context: Recombinant human (rh) IGF-I is now available to treat children with short stature resulting from severe primary IGF-I deficiency. This review from the Drug and Therapeutics Committee of the Lawson Wilkins Pediatric Endocrine Society discusses different aspects of rhIGF-I therapy, particularly with regard to potential advantages and disadvantages in comparison with the traditional use of rhGH for treatment of short stature. Evidence Acquisition: We used the Entrez-PubMed search engine to conduct a review of publications addressing IGF-I deficiency, the use of rhIGF-I, and treatment for short stature. Evidence Synthesis: rhIGF-I, as a twice-daily sc injection, is now approved for treatment of short stature in children with severe primary IGF-I deficiency, which may occur as a consequence of mutations in the GH receptor, defects in the post-GH receptor signaling pathway, and IGF-I gene defects. It is also approved for children with GH deficiency who develop neutralizing antibodies to GH. rhIGF-I significantly improves growth in these conditions. However, adult height may still be suboptimal, possibly due to lack of direct GH effects. Dosing regimens for rhIGF-I administration are under investigation, as are other indications for use of rhIGF-I. Conclusion: The use of rhIGF-I is justified in conditions approved by the Food and Drug Administration. Until more substantial data become available, the use of rhIGF-I outside Food and Drug Administration recommendations should only be investigational.