BACKGROUND Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare and severe progressive disease with multiple clinical manifestations and organ damage. Usually, it requires long-term monitoring of the state of many organs due to the gradual character of its manifestations. CASE REPORT We report a case of a long-term follow-up of a patient with eosinophilic granulomatosis with polyangiitis with emphasis on specific clinical features in this patient. A 64-year-old man was being followed up for 10 years. The initial diagnosis was allergic bronchial asthma; however, as new clinical signs and symptoms developed, the diagnosis of EGPA became obvious. A positive treatment response was seen, mainly manifested as reduced polyneuropathy. Meanwhile, bronchial asthma remained uncontrolled and bronchiectasis and Klebsiella pneumoniae colonization developed despite the combination treatment with prednisolone and methotrexate. Furthermore, the patient suffered a cerebral ischemic infarction. During the last hospital admission, severe uncontrolled bronchial asthma complicated with pneumonia resulted in the patient's death. CONCLUSIONS This clinical case shows the gradual development of EGPA with multiple-organ involvement, including respiratory manifestations and peripheral and central nervous system damage. Immunosuppressive treatment combined with complications of EGPA could have contributed to severe pneumonia development and death of the patient.