BACKGROUND Although the association between parental coronary artery disease (CAD) and its risk factors in the offspring is known, the timing and the course of development of risk factors from childhood to adulthood in the offspring is not known. OBJECTIVE To examine the association between parental CAD and longitudinal changes in risk factor profile from childhood to young adulthood in offspring. METHODS Cohort study. METHODS Bogalusa, La, a semirural, biracial community. METHODS Individuals with clinically verified parental history of CAD (n=271) vs those without such a history (n = 1253) Mean age at first CAD event was 50 years for fathers and 52 years for mothers. METHODS Body mass index, subscapular skinfolds, blood pressure, and triglyceride, cholesterol (total, very low-density lipoprotein [VLDL-C], low-density lipoprotein [LDL-C], and high-density lipoprotein [HDL-C] cholesterols), glucose, and insulin levels. RESULTS The offspring of parents with CAD were consistently overweight beginning in childhood. Their levels of total serum cholesterol, LDL-C, plasma glucose, and insulin became significantly higher at older ages, because of a higher rate of increase in these risk factors over time. In adulthood, the offspring with a positive parental history had a higher prevalence of obesity (body mass index >85th percentile in the National Health and Nutrition Examination Survey I, 35% vs 26%, P=.01), elevated total cholesterol (>6.2 mmol/L [240 mg/dL], 8.4% vs 4.8%, P=.05) and LDL-C levels (>4.1 mmol/L [160 mg/dL], 12.4% vs 4.7%, P=.05), and hyperglycemia (glucose, >6.6 mmol/L, 2.7% vs 0.4%, P<.001), as well as a higher coexistence of these conditions (P=.01). Further, the prevalence of dyslipidemia, either involving only LDL-C or LDL-C in combination with HDL-C or triglycerides or both, was significantly higher in the adult offspring with parental CAD. CONCLUSIONS Offspring of parents with early CAD were overweight beginning in childhood and developed an adverse cardiovascular risk factor profile at an increased rate. These observations have important implications for prevention and intervention.