A 56-year-old woman with a history of cerebral amyloid angiopathy (CAA) complicated by prior intracranial hemorrhage (ICH) was evaluated for an asymptomatic ischemic stroke discovered on screening brain MRI. On echocardiogram, she was found to have a mass on her mitral valve and strongly positive antiphospholipid antibodies. She was diagnosed with nonbacterial thrombotic (Libman-Sacks) endocarditis associated with the primary antiphospholipid syndrome (APS). The treatment decision was complicated by the history of CAA with ICH within the last year with very high risk for bleeding complications if on anticoagulation. A multidisciplinary decision was made to initiate a trial of warfarin for 3 months. She fared well and warfarin was continued. She has not had any further bleeding or ischemic events over the subsequent 1.5 years and remains on warfarin for her APS.