Background: Lung cancer is the leading cause of cancer death for people living with HIV (PWH), and this group experiences lung cancer outcome disparities for unclear reasons. To better understand these disparities, we explored potential differences in adverse events since the start of chemotherapy, or radiation therapy (RT), among PWH with stage I-IIIA non-small cell lung cancer (NSCLC). Methods: Our matched case-cohort study used data from SEER-Medicare data on stage I-IIIA NSCLC diagnosed between 2000 and 2013. We identified 809 early stage NSCLC patients with HIV; 40 were treated with chemotherapy and 60 with RT. For each therapy type, a PWH case was matched, by age, sex, and cancer stage to 10 controls with no evidence of HIV infection. Outcome Measures: Acute severe chemotherapy or RT toxicity ascertained by a relevant inpatient diagnosis within 6 months of chemotherapy initiation or chronic toxicities from outpatient diagnostic codes within 24 months. We also evaluated overall (all-cause) and lung cancer-specific survival. Results: Among hematologic toxicities, PWH treated with chemotherapy were more than twice as likely to develop severe anemia [odds ratio [OR] = 2.3 (95% confidence interval [95% CI]: 1.2-4.6)]; but not neutropenia or thrombocytopenia (both p > 0.06). Among patients receiving chemotherapy, HIV was not associated with any other severe acute toxicities including fever, infection, nausea, renal dysfunction, and septicemia. For chronic complications, PWH had increased risk of neuropathy (OR 4.2; 95% CI: 1.3-13.6). Overall, HIV was associated with an increased count of chemotherapy complications seen per patient [p = 0.02]. PWH receiving chemotherapy had worse all-cause mortality (hazard ratio (HR) = 1.7; 95% CI: 1.2-2.4) and higher lung cancer-specific mortality (HR 1.8; 95% CI: 1.2-2.7) compared to uninfected persons after adjusting for treatment with surgery. In contrast, HIV was not significantly associated with severe RT complications (esophagitis, pneumonitis or hemoptysis), although all-cause mortality (HR 1.5; 95% CI: 1.1-2.0) and lung-cancer specific mortality (HR 1.5; 95% CI: 1.1-2.0) were higher among PWH receiving RT after adjusting for treatment with surgery. Conclusions: Antiretroviral-era PWH with early stage lung cancer experienced more frequent complications after chemotherapy but not radiotherapy compared to matched uninfected persons. These toxicities may have led to treatment alterations potentially contributing to outcome disparities seen in this high-risk group.