Several large retrospective cohort studies demonstrate that pre-eclampsia is common in asthmatics. Whether airway hyperresponsiveness (AHR), a hallmark of asthma, is associated with pre-eclampsia is unknown. We measured AHR, using a methacholine challenge, and atopy in 19 women 3-60 months postpartum following pre-eclamptic or normotensive pregnancies. The geometric mean (95% CI) concentration of methacholine required to produce a >20% fall in the forced expiratory volume in 1 second (PC20 FEV1) was 8.9 (2.2-36) mg/ml in pre-eclamptics versus 72 (32-131) mg/ml in controls (P = 0.01) and 9 (1.9-40) mg/ml in atopic pre-eclamptics without asthma versus 54 (17-174) mg/ml (P = 0.038) in matched controls. Therefore, AHR was increased in women who have had pre-eclampsia. This association and its possible mechanisms warrant further investigation.