Diffuse alveolar haemorrhage and central nervous system vasculitis are life-threatening complications of anti-neutrophil cytoplasmic antibody-associated vasculitis. The simultaneous occurrence of diffuse alveolar haemorrhage and central nervous system vasculitis is a rare presentation of antibody-associated vasculitis. Its diagnosis by histopathology is difficult because biopsy is difficult to perform, and urgent treatment is needed. We report a case of a Japanese man with diffuse alveolar haemorrhage and central nervous system vasculitis associated with antibody-associated vasculitis. New classification criteria may be needed for diffuse alveolar haemorrhage and central nervous system vasculitis associated with systemic vasculitis. When antibiotic-resistant atypical bilateral pneumonia is noted in the acute phase of a cerebral stroke, with elements suggestive of vasculitis, clinicians should be aware that diffuse alveolar haemorrhage and central nervous system vasculitis may occur simultaneously.