Aims: To assess the association between cytomegalovirus and Type 2 diabetes among 6664 participants from the National Health and Nutrition Examination Survey. Methods: We used existing data from adults aged 20–49 years who participated in the National Health and Nutrition Examination Survey from 1999 to 2004. Cytomegalovirus status was determined using cytomegalovirus-specific immunoglobulin G antibodies. Prevalent Type 2 diabetes was assessed through self-report or a plasma fasting glucose of ≥7 mmol/l. Logistic regression models were used to evaluate the association between Type 2 diabetes and cytomegalovirus seropositivity after adjustment for age, gender, race/ethnicity, smoking status, education, BMI and physical activity. Results: In a univariate model, the crude odds of Type 2 diabetes were 47% higher in those who were cytomegalovirus-seropositive vs cytomegalovirus-seronegative. The association was attenuated and no longer significant after adjustment for age and other covariates: the odds ratio for diabetes was 1.09 (95% CI 0.71 to 1.66) for cytomegalovirus-seropositive vs -seronegative individuals. Conclusions: Our study suggests that the association between cytomegalovirus and Type 2 diabetes is explained by age and other risk factors for diabetes.