OBJECTIVE: To determine whether spouses of patients with type 2 diabetes have an increased risk of diabetes compared with spouses of subjects with normal glucose tolerance. RESEARCH DESIGN AND METHODS: A random sample of spouses of patients with type 2 diabetes (group 1S) attending a general practice diabetes clinic was compared with spouses of nondiabetic subjects (as determined by oral glucose tolerance test [OGTT]) (group 2S). Spouses in both groups underwent OGTT, fasting lipid profile, and blood pressure (BP) measurements. RESULTS: A total of 245 subjects in group 1S and 234 subjects in group 2S underwent OGTT. Group 1S had a significantly higher incidence of fasting glucose, impaired glucose tolerance, or type 2 diabetes (19.1 vs. 9.4%). Group 1S also had higher fasting glucose and triglyceride levels, higher BMI, and a trend toward higher BP. Multivariate logistic regression analysis, adjusted for BMI and age, showed the risk of diabetes in the spouse of a patient with diabetes was 2.11 (95% CI 1.74-5.1), as compared with the spouse of a subject with normal glucose tolerance. Similarly, the risk of any degree of glucose intolerance in a spouse of a patient with type 2 diabetes was 2.32 (1.87-3.98), as compared with a spouse of a subject with normal glucose tolerance. CONCLUSIONS: Spouses of patients with type 2 diabetes have a significantly increased risk of glucose intolerance and type 2 diabetes, and they should be classified as high risk for diabetes. This finding has implications for screening programs, which should include spouses of subjects with diabetes.