The tridecapeptide neurotensin has been implicated in the pathogenesis of cardiometabolic disease. Its stable precursor, pro-neurotensin/neuromedin N (pro-NT/NMN), has been associated with composite cardiovascular outcomes including coronary heart disease (CHD) and stroke. The exclusive association of pro-NT/NMN with ischemic stroke has not been evaluated. We conducted a prospective case-cohort study in the REasons for Geographic And Racial Differences in Stroke (REGARDS) study. From 2003 to 2007, REGARDS enrolled 30,239 white or black adults aged ⩾ 45 years. Baseline fasting pro-NT/NMN was measured by immunoassay in the analytic sample including 448 incident ischemic stroke cases and 818 random cohort sample participants. A total of 464 ischemic strokes occurred. Risk of stroke was assessed with a Cox proportional-hazards model incorporating demographic covariates and a second adding stroke risk factors. Increased pro-NT/NMN was associated with ischemic stroke in the demographic model overall (hazard ratio (HR) per standard deviation (SD) pro-NT/NMN 1.16, 95% confidence interval (CI) 1.01-1.33) and in men (HR per SD pro-NT/NMN 1.25, 95% CI 1.04-1.50); HRs were attenuated in the risk factor model. Pre-existing diabetes mellitus and CHD were the largest confounders of ischemic stroke risk, each accounting for an estimated 19% of the association of pro-NT/NMN with ischemic stroke observed in the demographic model. There were no significant interactions of race or sex with pro-NT/NMN. Further research on associations of pro-NT/NMN with stroke risk factors such as diabetes mellitus is indicated.