Thrombocytosis in post-splenectomy patients with hereditary spherocytosis (HS) is usually not attended by an increased risk of thrombosis. Review of the literature revealed HS in association with pulmonary thrombosis, portal vein thrombosis, and cerebral infarction in two brothers, TTP in an asplenic patient and a patient with corpora cavernosum thrombosis causing segmental priapism. We report a case of a 30-year-old white male with HS who presented with hemoptysis 29 years after splenectomy. Work-up revealed a hypercoagulable state with thrombocytosis and recurrent pulmonary emboli resulting in severe pulmonary hypertension, cor pulmonale, atrial flutter, and syncope.