A mechanical heart valve thrombosis during pregnancy is one of the most lethal conditions to experience due to its detrimental effects on both mother and fetus. Cardiac surgery during pregnancy is reserved for cases where medical treatment fails due to harmful maternal and fetal effects. A 24-year-old female in the 38th week of pregnancy was admitted to the emergency room with aggravated dyspnea, tachypnea, and palpitations. She had 2 previous cardiac operations in her medical history. A stuck mechanical valve was diagnosed in the mitral position via transthoracic echocardiography, which had resulted from her decision to cease taking warfarin when planning to become pregnant. In pregnant patients who have prosthetic mechanical valve thrombosis, surgical approach should be considered depending on the conditions of the mother and the baby. When emergency delivery of the baby is feasible, emergent surgical treatment should be utilized for patients who are in critical condition.