Rabson-Mendenhall syndrome(RMS) is first characterized in 1955 by Rabson and Mendenhall. RMS is a rare autosomal recessive variant with insulin resistance. This is due to insulin receptor mutations or other target-cell defects in insulin action. General findings include acanthosis nigricans, hypertrichosis, onychauxis, growth retardation, precocious puberty, genital enlargement, protuberant abdomen and xerotic skin. Characteristic oral and maxillofacial findings include dental dysplasia, coarse facial skin, prognathic jaw and fissured tongue. In this case report, dental characteristics of a 4-year old boy with Rabson-Mendenhall syndrome are described.