The etiology of postpartum eclampsia and hypertension remains controversial. Recent reports have suggested a possible idiosyncratic hypertensive reaction associated with the use of bromocriptine mesylate. The purpose of this study was to determine whether bromocriptine, used for lactation suppression, is a risk factor for postpartum hypertension. In 1813 consecutively delivered staff patients, blood pressures at three separate home visits were obtained between 3–21 days postpartum. Postpartum hypertension, defined for the purposes of this study as systolic pressure of 140 mmHg or greater and/or diastolic pressure of 90 mmHg or greater on any of the three home visits, was the dependent variable; bromocriptine exposure was the independent variable. Covariates included age, race, chronic hypertension, pregnancy-induced hypertension, and antihypertensive medication. Discriminant analysis, including the first-order interactions, revealed that race, history of chronic hypertension, pregnancy-induced hypertension, and antihypertensive medication contributed significantly to postpartum hypertension (F (7, 1803) = 107.9; P < .001, explained variance 30%). Of all the interaction terms, only the bromocriptine by pregnancy-induced hypertension interaction was significant. These findings support the contention that patients with antepartum pregnancy-induced hypertension who receive bromocriptine for lactation suppression are at increased risk for postpartum hypertension. Avoiding the elective use of this drug in patients with pregnancy-induced hypertension might constitute a reasonable clinical response to these findings.