The purpose of the paper is to identify maternal drug use that may be associated with an increased risk for cardiac defects in the offspring. A case-control study was performed with cases (cardiovascular defects without known chromosome anomalies) being identified from three Swedish health registers (n=5015) and controls being all infants born in Sweden during the period 1 July 1995-2001 (n=577,730). Information on drug exposure was obtained by interview in early pregnancy. Associations between maternal drug use and infant cardiovascular defect were identified for insulin, antihypertensives, fertility drugs, erythromycin, naproxen, anticonvulsants, nitrofurantoin, clomipramine, and budesonide in nasal preparations. Some of these associations are probably due to confounding from underlying disease or complaint, some may be due to multiple testing, some may be true drug effects. Further studies are needed to verify or reject these associations.