Abstract: OBJECTIVE To analyze the demographic and epidemiological characteristics of human immunodeficiency virus infection/acquired immunodeficiency syndrome (HIV/AIDS) patients aged 50 and above in a district of Beijing, and to provide a basis for formulating precise prevention and control measures for AIDS in this population. METHODS Information from the AIDS epidemic module report managed by the China Information System for Disease Control and Prevention was collected. Data on HIV/AIDS patients aged 50 and above residing in a district of Beijing from 2014 to 2024, along with their initial CD₄⁺ T lymphocyte (CD4) test results, were selected. The approximate time of infection was inferred based on the CD4 results. RESULTS A total of 136 newly reported HIV/AIDS cases aged 50 and above were identified in a district of Beijing from 2014 to 2024. The proportion of new cases among the total reported cases remained unchanged over the years (χ²=16.224, P=0.093). The primary route of infection was male-to-male sexual transmission, with a statistically significant difference in the proportion of infections through heterosexual transmission between males and females (χ²=10.716, P=0.001). Based on the initial CD4 cell test results, the inferred time of HIV infection was concentrated at ≥8 years, with a relatively high proportion of late-discovered cases. There was no statistical difference in the composition ratio between the time of infection and the route of infection (homosexual/heterosexual) (χ²=0.632, P=0.890). CONCLUSIONS Late-discovered cases exist among newly reported HIV/AIDS patients aged 50 and above in a district of Beijing. It is essential to further strengthen health education methods targeting the elderly population, expand active testing, and reduce secondary transmission to families and healthy individuals.