Convulsive crisis is a transient disturbance of cerebral function, and the etiology of which may be manifold. Its clarification is essential for establishing adequate therapy and seizure control. In the pregnancy-puerperal cycle, eclampsia is the most common cause of it, but brain tumor, epilepsy and other disorders are part of the differential diagnosis. We report a case of seizure triggered by tumor in a primigest, 22 years old, at 38 weeks’ gestation with premature rupture of membranes. Cesarean section was performed due to non-reassuring fetal condition. On the second day of puerperium, she presented recurrent episodes of generalized tonic-clonic seizures and elevated blood pressure. She received magnesium sulfate for 24 hours and persisted with severe headache. Magnetic resonance imaging of the brain showed an expansive lesion in the left frontoparietal region. The patient underwent intracranial microsurgery on the eighth day after cesarean section, with complete resection of the lesion and anatomopathological diagnosis of schwannoma. She went through good postoperative evolution, without neurological deficits, and stayed on phenobarbital, with no seizures until 6 months of follow-up. From the case we conclude that although the first diagnosis in pregnant or puerperal women with seizures should be eclampsia, there are other causes, such as brain tumor and Posterior Reversible Encephalopathy Syndrome (PRES). Careful evaluation is required, especially in refractory cases and not responding to usual treatment.