Objectives: To report a rare case of moyamoya syndrome with primary antiphospholipid syndrome (APS). Clinical Presentation and Intervention: A 41-year-old woman was admitted with sudden onset of left-sided hemiparesis. Magnetic resonance imaging and magnetic resonance angiography of the brain showed characteristic features of moyamoya vessels. Laboratory investigations revealed raised levels of anticardiolipin antibody. She made a complete and uneventful recovery with aspirin and intensive physiotherapy over a period of 2 weeks. Conclusion: The association of APS and moyamoya disease may present a dilemma in management. While APS is often considered to be an indication for giving anticoagulation, a trial of antiplatelet agents is preferable to anticoagulation because of the risk of bleeding from the fragile moyamoya vessels.