The Authors report 3 cases of "Congenital Smooth Muscle Hamartoma" (CSMH). CSMH presents as congenital patches or slightly indurated plaques with prominent overlying hair, often hyperpigmented. Histopathologic examination showed increased numbers of well-defined smooth muscle bundles in the superficial and deep dermis. CSMH and Becker's nevus should be considered in the differential diagnosis of any congenital hairy hamartoma.