Immune checkpoint inhibitors (ICIs) are first line treatment for advanced lung cancer. Tobacco use is a shared risk factor for lung cancer and chronic obstructive pulmonary disease (COPD). Although many patients with COPD and lung cancer receive ICIs, the impact of ICIs on COPD is unknown. Here, we evaluated whether ICI treatment was associated with increased COPD disease burden. We conducted a retrospective cohort study of lung cancer patients with and without preexisting COPD who received ICIs from 2011-2021 at The Ohio State University (OSU). For all patients, number of steroid courses and respiratory related hospitalizations were recorded. For those with COPD, COPD medications were collected at and after ICI initiation. Pulmonary function tests, COPD exacerbations, and COPD-related hospitalizations were compared before and after ICI treatment. Linear and generalized mixed models were used to account for potential confounders of worsening COPD. Among 1083 lung cancer patients who received ICIs, 585 (54.0%) had pre-ICI COPD. Patients with COPD were prescribed more COPD medications (3 [1, 4] vs 1 [0, 3],