Objective: To determine whether the risk of pregnancy-induced hypertensive disorders (PIHD) is higher in patients with the polycystic ovary syndrome (PCOS) than in non-PCOS controls, matched for age and parity. Study Design: Retrospective analysis of eighty-one patients with PCOS, consecutively becoming pregnant during a seven-year period. Each PCOS-patient was matched for age and parity with one control patient. Chi-squared, Mann–Whitney or Fisher's exact-tests were used for statistical analysis. Results: Overall incidence of PIHD was similar in both study groups. However, incidence of preeclampsia was significantly higher in patients with PCOS than in controls ( P=0.02). This higher incidence can not be explained by body mass index, endocrine profile before pregnancy, induction of ovulation or treatment regimens. Conclusions: PCOS-patients are at a significantly higher risk for preeclampsia than non-PCOS controls.