Opportunistic infections (OIs) are the most significant complication of human immunodeficiency virus (HIV) infection. The prevalence of OIs differs among various countries in part due to different climates and socio-economic conditions. We, therefore, carried out the retrospective study at the Public Health Clinical Center of Chengdu, Sichuan to comprehensively investigate the prevalence of OIs, predictors of OIs, and risk factors for in-hospital death among HIV-infected patients. Sichuan in West China is characterized by the largest population living with HIV/Acquired immunodeficiency syndrome (AIDS) across China. In total, we reviewed 954 cases of HIV infection, admitted to the hospital during January 2014 to December 2015, and found that bacterial pneumonia (25.8%) was the most common OIs, followed by candida infection (18.3%), Pneumocystis jiroveci pneumonia (11.9%), tuberculosis (11.5%), infectious diarrhoea (9.3%), cryptococcus infection (7.3%), cytomegalovirus infection (4.9%), toxoplasmosis (4.6%), hepatitis C (4.0%), nontuberculous mycobacteria desease (2.2%) and Penicillium marneffei infection (0.3%). We also found two strongest risk factors for in-hospital mortality: CD4+T cell counts of less than 100 cells/μL and not receiving antiretroviral therapy. Moreover, the study revealed the specific pathogens causing bacterial pneumonia and/or candida infection, the effect of tuberculosis on CD4+T cell counts, and the drug resistance of Mycobacterium tuberculosis among HIV-infected and non-HIV-infected patients. The present findings may aid in the clinical diagnosis and treatment of HIV-infected patients, and could help developing efficient public health strategies in China.