Familial combined hyperlipidemia (FCHL) is the most frequent genetic lipid abnormality in humans, with a 5- to 10-fold increased risk of early myocardial infarction. Familial combined hyperlipidemia has been proposed as the leading cause of dyslipidemia in familial dyslipidemic hypertension (FDH). It was the objective of this study to quantify and analyze the simultaneous occurrence of hypertension and hyperlipidemia in FCHL families. We assessed blood pressure (BP) and hyperlipidemia in 27 families with FCHL (235 relatives and 140 spouses, aged 30 to 60 years). Hypertension was defined as a BP more than 140/90 mm Hg, or the use of antihypertensive medication. Multiple backward linear regression analysis was used to derive a biological formula describing BP in FCHL families. One-third of 27 FCHL families were diagnosed with FDH. Sixty-four of 235 (27.2%) relatives had dyslipidemic hypertension (DH), compared to 20 of 140 (14.3%) spouses (P = .005); odds ratio = 2.25 (95% confidence interval 1.29-3.91). Multiple linear regression analysis showed that age, FCHL status, and waist circumference significantly contributed to systolic blood pressure (SBP) in female FCHL relatives. In conclusion, in FCHL we defined age, waist circumference, and hyperlipidemia as predictors of SBP. This study indicates that visceral adipose tissue strongly contributes to the high prevalence of DH in FCHL families. Reduction of visceral fat should be tested as a potential therapeutic intervention for hyperlipidemia and hypertension in FCHL individuals.