Background. Description of incidence, clinical signs, symptoms, and consequences of eclampsia in Scandinavia, and assessment of substandard care and potential preventability. Methods. A descriptive cohort study including all women giving birth in a 2-year period (mid-1998–mid-2000) in Scandinavia. Notifications of eclampsia cases were obtained from all obstetric units at 3-monthly intervals. All patient files were reviewed, and systematic audit was performed to identify potentially preventable cases by using predefined criteria. Main outcome measures. Signs and symptoms preceding the eclamptic seizure, the standard of medical care, maternal and perinatal morbidity, and mortality were all recorded. Potentially preventable cases through improved care and cases eligible for primary prophylactic magnesium sulfate (MgSO4) were estimated. Results. The incidence of eclampsia was 5.0/10 000 maternities (CI = 4.3–5.7/10 000). Eighty-six percent had a diagnosis of pre-eclampsia before the seizure. Nine of 10 had at least one physical complaint before the first seizure, severe headache being the most common symptom, occurring in two-thirds. Most seizures (90%) occurred after admission to hospital. By audit, 89 cases (42%) were classified as having received substandard care. Prophylactic use of magnesium sulfate might have reduced the number of eclampsia cases by 35 (17%). Conclusions. Eclampsia occurred mainly in hospital and the majority of women had symptoms heralding the seizure. In retrospect, nearly half of the cases were found potentially preventable by timely intervention, improved medical care, and systematic use of prophylactic treatment with MgSO4.