Over the past two decades, antiresorptive agent-related osteonecrosis of the jaw (ARONJ) has become a growing concern. We examined the incidence of ARONJ and identified its risk factors in lung cancer patients in the real-world clinical setting. To our knowledge, we are the first to do so. We retrospectively analyzed lung cancer patients with bone metastases who had received anti-resorptive agents (zoledronate or denosumab) at the National Hospital Organization Kyoto Medical Center from October 2012 to September 2018. All ARONJ cases were diagnosed by the dentists according to the established diagnostic criteria. A total of 171 patients were reviewed, 13 (7.6%) of whom experienced ARONJ. Among the 13 patients, six (46.2%), four (30.8%) and three (23.1%) had adenocarcinoma, squamous carcinoma and not otherwise specified, respectively. ARONJ was stage 2 in three (23.1%) patients and stage 3 in 10 (76.9%). More cycles of antiresorptive agents (odds ratio [OR] = 11.54; 95% confidence interval [CI], 2.47-53.99; P < 0.01), use of immune checkpoint inhibitors (ICIs; OR = 5.05; 95% CI, 1.56-16.37; P < 0.01) and longer survival duration (≥2 years; OR = 12.16; 95% CI, 3.17-46.65; P < 0.01) were independently associated with ARONJ in a multivariate analysis. The incidence of ARONJ was relatively high in lung cancer patients with bone metastases. When using antiresorptive agents, oncologists should closely monitor patients for ARONJ during the course of treatment and regularly consult with dentists, especially in patients receiving ICIs. © 2020 John Wiley & Sons Australia, Ltd.