OBJECTIVE: To document the existence and clinical characteristics of three large families with multigenerational inheritance of early-onset type 2 diabetes in Jamaica. METHODS: Three probands from large families with multigenerational inheritance of early-onset type 2 diabetes in at least three generations were detected at the University Hospital of the West Indies in Jamaica. Each proband at the time of diagnosis was < 25 years of age, was lean, and did not require insulin therapy. Clinical, metabolic, and genetic assessments were undertaken to profile the diabetes in the three families. RESULTS: Three pedigrees-BK, SU, and CA-consisting of 38, 48, and 113 members, respectively, with multigenerational inheritance of early-onset type 2 diabetes in at least three generations, were investigated. The mean age at diagnosis of the three pedigrees was 31.5 ± 2.9 years, with 10 persons detected below 25 years of age. Findings suggestive of overweight, insulin resistance, low insulin secretion, dyslipidemia, and mild intra-abdominal obesity were present. Islet cell antibodies and sequence variants in MODY1 to -6 genes were absent. CONCLUSIONS: Large families demonstrating multigenerational inheritance of diabetes and other characteristics consistent with early-onset type 2 diabetes are present in the Jamaican population.