Cohen syndrome is a rare, genetic, connective-tissue disorder with the genetic abnormality linked to chromosome 8q22. The diagnosis of Cohen syndrome is based on the recognition of certain clinical findings, which include mental retardation, typical morphologic stigmata (e.g., truncal obesity, hypotonia, short philtrum, prominent frontal incisors, high-arched palate, narrow hands and feet), and characteristic ophthalmologic abnormalities. We report a patient manifesting the typical characteristics of Cohen syndrome with seizure and hyperinsulinemia.