A 47-year-old Japanese woman developed antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) complicated by a rare combination of aortitis and hypertrophic pachymeningitis. Despite the therapy with prednisolone and cyclophosphamide, the aortitis was not ameliorated. However, after cyclophosphamide was replaced with intravenous tocilizumab, the aortitis was improved, and the prednisolone dose was successfully tapered to 4 mg/day without elevation in C-reactive protein and myeloperoxidase ANCA (MPO-ANCA) levels. Several studies have reported that tocilizumab is effective for aortitis associated with Takayasu's arteritis and giant cell arteritis. On the other hand, we succeeded to improve the aortitis in AAV with monthly administration of tocilizumab. Moreover, we successfully controlled disease activity and enabled the tapering of prednisolone to 4 mg/day without relapses of AAV symptoms and elevated MPO-ANCA levels. It indicates that tocilizumab may be therapeutically beneficial for not only aortitis but also AAV itself. In conclusion, tocilizumab was effective in treating glucocorticoid- and cyclophosphamide-resistant AAV-associated aortitis. This is the first report demonstrating the successful treatment of AAV-associated aortitis using tocilizumab.