Hemihyperplasia can be found as an isolated abnormality, or as a predominant associated feature of an asymmetric overgrowth syndrome. This report describes 2 patients with hemihyperplasia-multiple lipomatosis syndrome. The finding of hemihyperplasia prompts careful examination for associated lipomatous lesions. Close follow-up is required because progressive growth of lipomatous lesions can be encountered as well as recurrence after excision. (C) 2010 Elsevier Inc. All rights reserved.