<p>Background human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) remains a critical global public health concern. However, the short-term impacts of traffic-related air pollution (TRAP) on mortality from leading causes among people living with HIV/AIDS(PLHIV) have not been well characterized. Methods a time-stratified case-crossover study was conducted using mortality records of PLHIV in Anhui Province, China, from 2015 to 2022. Daily concentrations of traffic-related pollution, including fine particulate matter (PM₂.₅), inhalable particles (PM₁₀), nitrogen dioxide (NO₂), and carbon monoxide (CO), along with meteorological data, were incorporated into conditional logistic regression models.Lagged effects and exposure-response relationships were assessed, and subgroup analyses were stratified by sex, age, marital status, educational level, occupational category, seasons, and clinical stage. Results among the 2,739 recorded deaths, the leading causes were neoplasms (20.6%), respiratory diseases (20.3%), and circulatory diseases (16.9%). On case days, concentrations of PM₂.₅, PM₁₀, and NO₂ were modestly elevated compared to control days. Significant associations were observed between pollutant exposure and mortality risk, with PM₂.₅, PM₁₀, and NO₂ linked to increased risk in the neoplasm and respiratory groups, and CO exposure associated with circulatory-related deaths. Dose–response curves indicated monotonic increases in risk beyond pollutant-specific thresholds. Subgroups including men, people under 65 years of age, farmers, people with low educational attainment, unmarried, and individuals at the AIDS stage are more vulnerable. Conclusions short-term exposure to traffic-related air pollution significantly increases the risk of death from major comorbidities among PLHIV. These findings highlight the need for targeted environmental health interventions addressing vulnerable populations.</p>