Introduction: Most cases of sudden cardiac death (SCD) in the general population occur primarily among persons who do not have any prior history of clinical heart disease. Hypothesis: After evaluating a comprehensive panel of traditional and novel cardiovascular risk factors in two, large, racially diverse, population-based cohorts, we sought to develop a predictive model of SCD among US adults without a history of cardiovascular disease. Methods: We evaluated a series of 26 demographic, clinical, laboratory and electrocardiographic measures in participants who were free of baseline cardiovascular disease in the Atherosclerosis Risk in Communities (ARIC) Study (n=13,677) and the Cardiovascular Health Study (CHS) (n=3,650). Results: After a median follow-up of approximately 13 years, there were a combined total of 318 adjudicated SCD events for analysis. The following 11 risk factors were significant risk factors for SCD after meta-analyzing the findings from each cohort: age (per 5 years; HR 1.32, 95% CI [1.17 - 1.49]), male sex (HR 2.23; 1.70 - 2.93]), African American race (HR 1.62, 1.19 - 2.20), current smoking (HR 2.19, 1.65 - 2.92), low physical activity (HR 1.42, 1.09 - 1.85), hypertension (HR 1.82, 1.37 - 2.42), diabetes (HR 2.49, 1.86 - 3.34), low serum albumin (per 0.3 g/dL decrease; HR 1.38, 1.20 - 1.59), low HDL (<40 mg/dL in men and <50 mg/dL in women; HR 1.37, 1.05 - 1.80), eGFR<60 ml/min/1.73m2 (HR 1.77, 1.16 - 2.71), and a prolonged QTc interval (≥440 milliseconds in men or ≥460 milliseconds in women; HR 2.08, 1.54 - 2.80). Over a 10-year follow-up period, a model combining these risk factors showed good to excellent discrimination for SCD risk (C statistic 0.831 in ARIC and 0.745 in CHS). Serum biomarkers including C-reactive protein (CRP), NT-pro-brain natriuretic peptide (BNP) and high sensitivity troponin T were not significant risk factors and did not enhance SCD risk prediction when added to the final multivariate model. Conclusions: A prediction model including demographic, clinical, laboratory, and electrocardiographic variables provided accurate information on the future SCD risk in middle-aged and elderly populations.