This case report presents a 25-year-old gestational patient with a history of multiple cesarean sections, who developed a myasthenic crisis postpartum, complicated by preeclampsia with severe features. Despite unremarkable prenatal tests, the patient experienced respiratory failure requiring mechanical ventilation. Prompt neurological consultation led to the diagnosis of myasthenia gravis (MG) and initiation of appropriate treatment with intravenous immunoglobulins and Pyridostigmine. However, the contraindication of magnesium sulfate due to MG posed challenges in managing preeclampsia. The patient responded well to alternative antihypertensive therapy with hydralazine. This case underscores the importance of early recognition and management of MG in the peripartum period, as well as the need for multidisciplinary collaboration to optimize maternal and fetal outcomes in complex medical scenarios. Further research into alternative treatments for preeclampsia in MG patients is warranted to improve clinical management strategies.