Ventricular function has been studied in 43 patients with the peripartum cardiac failure (PPCF) syndrome which occurs around Zaria. All patients had an echocardiogram on admission and 10 patients had right heart catheterization. Despite the gross edema, left ventricular function assessed by echocardiography and systolic time intervals was relatively good and the estimated cardiac output were high. At catheterization, although the pressures were high, the cardiac outputs were greater than normal in four out of six patients. No patient had a low cardiac output. These findings are not compatible with a severe heart muscle disorder, or cardiomyopathy. We suggest that the primary event in PPCF of Zaria is fluid retention which leads to a form of high output cardiac failure. The postpartum practices in this area (taking high sodium diets and lying on heated beds) almost certainly cause the fluid to accumulate initially, but the heart may be unable to meet the demands either because of preexisting heart muscle disease or, more likely, because of a rise of the peripheral resistance due to the volume expansion, overburdens such dilated hearts and leads to myocardial damage. Since there are similarities between this condition and PPCF in temperate climates, it is possible that there is a common mechanism which the traditional practices of this area have unveiled.