AIMS: Cytomegalovirus (CMV) infection under immunosuppression sometimes causes death. This study aimed to elucidate risk factors for CMV infection in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). METHODS: Patients with AAV who underwent remission induction treatment at Okayama University Hospital between 2006 and 2016 were retrospectively analyzed. The primary outcome was the development of CMV infection within 3 months. RESULTS: Of the 111 patients, 13 (11.7%) patients developed CMV infection. Patients with CMV infection were older (p = 0.030) and had a higher body mass index (p = 0.029) in comparison to those without CMV infection. A higher proportion had a severe form (p = 0.001) and granulomatosis with polyangiitis (GPA) (p = 0.001), as well as a higher Birmingham Vasculitis Activity Score (p = 0.018) and C-reactive protein (p = 0.018) levels at baseline. Using logistic regression analysis, severe form and GPA were independent risk factors (odds ratio [OR] = 9.68, 95% confidence interval [CI] = 1.92-60.23, and OR = 7.46, 95% CI = 1.46-47.60, respectively). In addition, patients with CMV infection were more likely than those without infection to be glucocorticoid-related diabetes mellitus (p = 0.025). CONCLUSION: Our study highlights disease severity and subgroups of AAV as risk factors for CMV infection.