Protein S deficiency causing arterial ischemic stroke during pregnancy is uncommon. Delay or omission of treatment with perfusion therapies may worsen outcomes for both the mother and the fetus. In this paper, we report a case of an early pregnant woman with protein S deficiency and multiple history of chronic cerebrovascular disease who underwent successful thrombolysis and mechanical thrombectomy. The patient is a 35-year-old woman, eight weeks pregnant, with a history of protein S deficiency and chronic cerebrovascular disease, presenting with rightsided weakness and aphasia. Initial National Institutes of Health Stroke Scale was 10 with cranial magnetic resonance imaging findings of acute infarcts on the left caudate, lentiform nucleus, insula, and frontal lobe with a large vessel occlusion on the proximal M1 segment of the left middle cerebral artery. Intravenous thrombolysis and mechanical thrombectomy were performed with complete recanalization. The patient improved and delivered without any complications after 8 months. Protein S deficiency can contribute to arterial thrombosis including ischemic stroke. Arterial ischemic stroke and large vessel occlusion can cause significant disability if not treated appropriately. Reperfusion therapies in pregnant women show favorable outcomes and should be performed if the benefits outweigh the risks.