OBJECTIVE Evaluation of severe maternal morbidity in peripartum period leading to controlled ventilation in the obstetrical intensive care unit. METHODS A retrospective study was carried out during a period of three years, from March 1998 to March 2001, in the obstetrical intensive care unit (ICU) of Farhat Hached hospital, Sousse (Tunisia). METHODS Twenty obstetric patients requiring controlled ventilation were admitted in the ICU. Obstetric data included maternal age, gestational age, parity, diagnosis of the disease requiring controlled ventilation and maternal outcome. RESULTS A total of 24812 deliveries occurred during the study period at Farhat Hached maternal center. Twenty patients (0.08 percent) required controlled ventilation for a mean duration of 38 hours (range: five hours- 21 days). The mean age was 30 +3 years. Eight patients were primigravida. The mean gestational age was 33 +2 weeks. Seventeen patients (85 percent) underwent cesarean section. The mean duration in the ICU was six days (range: 5 hours - 34 days). There were six maternal deaths (30 percent). Maternal mortality was attributed to neurologic 40 percent, hemodynamic 30 percent or respiratory 30 percent failure which complicated eclampsia, hemorrhagic shock, pulmonary edema or sepsis. CONCLUSIONS There were 0.08 percent of obstetric patients requiring controlled ventilation. The serious maternal morbidity and the high mortality require better care of obstetric patients.