To develop a straightforward risk score for type 2 diabetes (DM2) screening to use in clinical practice. A sample of 6237 adult inhabitants of the Canary Islands (Spain) was randomly divided into two subgroups: one yielded data used to develop the instrument, and the other yielded data used for validation testing. Performance of the instrument was compared in persons with clinically diagnosed DM2 and undiagnosed diabetes. The risk score, calculated by multivariate logistic regression, included the potential risk variables that yielded the highest odds ratio in the univariate analysis. A cut-off point for screening purposes was established at a 99% negative predictive value. In men, variables included in the risk score were age, waist/height ratio, familial antecedents of diabetes, and systolic blood pressure (ROC curve 0.837, 95% CI: 0.803-0.871). In women, the risk score contained the same variables plus gestational diabetes history (ROC curve 0.874, 95% CI: 0.847-0901). Excluding systolic blood pressure from the score had no significant effect on the area under the curve. This instrument resulted valid only for people aged less than 55 years. This simple risk score for DM2 would be easy to apply in clinical practice.