The aims of our study were to measure autoantibodies to glutamic acid decarboxylase and autoantibodies to protein tyrosine phosphatase in patients with type 2 diabetes mellitus, patients with impaired glucose tolerance, and healthy controls of Asian origin from Birmingham, United Kingdom. According to our findings, 27% (9/33) of patients initially diagnosed with type 2 diabetes mellitus carry autoantibodies to GAD65.