Polyangiitis overlap syndrome is defined as systemic vasculitis that cannot be classified into one of the well-defined vasculitic syndromes. In this report, a female patient who presented with vasculitis-like and asthmatic symptoms was diagnosed as having polyangiitis overlap syndrome of granulomatosis with polyangiitis (GPA; formerly known as Wegener's granulomatosis) and eosinophilic granulomatosis with polyangiitis (EGPA; formerly known as Churg-Strauss syndrome). The patient fulfilled the American College of Rheumatology diagnostic criteria for GPA and EGPA. She was successfully treated with immunosuppressants and steroids and has been in remission for 20 months. It is important to establish a proper diagnosis and introduce an appropriate treatment modality in patients with this rare and serious pathology to prevent irreversible organ damage.