Objective To compare incidences, characteristics, management and outcome of eclampsia in the Netherlands and the UK. Design A comparative analysis of two population‐based prospective cohort studies. Setting All hospitals with consultant‐led maternity units. Population Women with eclampsia in the Netherlands (226) and the UK (264). Methods Comparison of individual level data from national studies in the Netherlands and the UK (LEMMoN 2004–06; UKOSS 2005/06). Main outcome measures Incidence, maternal complications and differences in management strategies. Results Incidences of eclampsia differed significantly between both countries: the Netherlands 5.4/10 000 deliveries versus UK 2.7/10 000 (relative risk RR 1.94, 95% confidence intervals 95% CI 1.6–2.4). The proportion of women with a preceding diagnosis of pre‐eclampsia was comparable between both countries (the Netherlands 42%; UK 43%), as was the proportion who received magnesium sulphate prophylaxis. Women in the Netherlands had a significantly higher maximum diastolic blood pressure (111 mmHg versus 95 mmHg, P < 0.001); significantly fewer received anti‐hypertensive medication (16% versus 71%; RR 0.2, 95% CI 0.1–0.3) and were treated less often with magnesium sulphate after their first fit (95% versus 99%; RR 0.96, 95% CI 0.92–0.99). Maternal death occurred in three cases in the Netherlands compared with zero in the UK. Conclusions The incidence of eclampsia in the Netherlands was twice as high compared with the UK when using uniform definitions. Women with eclampsia in the Netherlands were not managed according to guidelines, particularly with respect to blood pressure management. Changes in management practice may reduce both incidence and poor outcomes.