BACKGROUND: A positive parental history of myocardial infarction (MI) is an independent risk factor for cardiovascular diseases (CVD). However, different definitions of parental history have been used. We evaluated the impact of parental gender and age of onset of MI on CVD incidence. METHODS: Baseline data were collected between 1993 and 1997 in 10,524 respondents aged 40-65 years. CVD events were obtained from the National Hospital Discharge Register and Statistics Netherlands. We used proportional hazard models to calculate hazard ratios (HR) and 95% confidence intervals (CI) for CVD incidence and adjusted for lifestyle and biological risk factors. RESULTS: At baseline, 36% had a parental history of MI. During 10-year follow-up, 914 CVD events occurred. The age and gender adjusted HR was 1.3 (95% CI 1.1-1.5) for those with a paternal MI, 1.5 (1.2-1.8) for those with a maternal MI and 1.6 (1.2-2.2) for those with both parents with an MI. With decreasing parental age of MI, HR increased from 1.2 (1.0-1.6) for age ≥70 years to 1.5 (1.2-1.8) for age <60 years for a paternal MI and from 1.1 (0.9-1.5) to 2.2 (1.6-3.0) for a maternal MI. The impact of having a mother with MI before age 60 significantly differed in women [(2.9 (1.8-4.6)] and men [1.5 (0.9-2.6)]. Adjustment only slightly influenced HRs for maternal MI. CONCLUSIONS: Respondents with a parental history of MI have an increased CVD incidence, in particular with parental onset of MI before age 70. A maternal history of MI before age 60 was the strongest predictor of CVD incidence.