Context: Although dysglycemia is a risk factor for cognitive decline, it is unknown whether cognitive performanceamongyoung and apparently healthy adults affect the risk for impaired fasting glucose (IFG). Objective: This study aimed to characterize the relationship between cognitive function and the risk for IFG among young adults. Design and Setting: This was a retrospective cohort study utilizing data collected at pre-military recruitment assessments with information collected at the screening center of Israeli Army Medical Corps. Participants: Normoglycemic adults (n = 17 348) (free of IFG and diabetes; mean age 31.0 ± 5.6 y; 87% men) of the Metabolic Lifestyle and Nutrition Assessment in Young Adults (MELANY) cohort with data regarding their General Intelligence Score (GIS), a comprehensive measure of cognitive function, at age 17 y. Interventions: Fasting plasma glucose was assessed every 3-5 y at scheduled visits. Cox proportional hazards models were applied. Main Outcomes Measures: The main outcome of the study was incident IFG (≥100 mg/dL and<126 mg/dL) at scheduled visits. Results: During a median followup of 6.6 y, 1478 cases of IFG were recorded (1402 men). After adjustment for age and sex, participants in the lowest GIS category had a 1.9-fold greater risk for incident IFG compared with those in the highest GIS category. In multivariable analysis adjusted for age, sex, body mass index, fasting plasma glucose, family history of diabetes, country of origin, socioeconomic status, education, physical activity, smoking status, alcohol consumption, breakfast consumption, triglyceride level, white blood cell count, the risk for IFG was nearly doubled in the lowest GIS category compared with the highest GIS category (hazard ratio, 1.8; 95% confidence interval, 1.4 -2.3; P < .001). These results persisted when GIS was treated as a continuous variable and when the model was adjusted also for body mass index at the end of followup. Conclusions: This study demonstrates that lower cognitive function at late adolescence is independently associated with an elevated risk IFG in both men and women.