Background: While antiretroviral therapy (ART) has significantly improved survival rates of people living with HIV, some regions in Brazil still show a linear trend of growth in the opportunistic infections that cause HIV-associated mortality. We aimed to describe HIV-associated morbidity and mortality among hospitalized medical patients in a tertiary care hospital in Manaus, in the Brazilian Amazon, by investigating clinical data and immunologic biomarkers in order to assess predictive factors of mortality in this patient group. Methods: We prospectively measured concentrations of cytokines Th1/Th2/Th17 and soluble CD14 (sCD14) and reviewed the laboratory parameters and opportunistic infections in outcomes of either death or discharge of eighty-three HIV/AIDS patients who were admitted in 2017-2018 to the Fundação de Medicina Tropical Doutor Heitor Vieira Dourado (FMT-HVD) in Manaus. Results: The mortality in the sample studied was 20.5%. Tuberculosis (TB) showed a relative risk (RR) =1.86 (confidence interval (CI) 1.14 to 2.81: and p = 0.026), and weight loss was the symptom (RR=1.81; CI: 1.21 to 2.53 and p = 0.007) most highly associated with the death outcome in HIV/AIDS inpatients. Univariable analyses showed that the eosinophil count, platelet distribution width (PDW), and alanine aminotransferase were the only laboratory parameters that differed among patients who died. In relation to cytokines and sCD14 levels, no differences were found between those who died or were discharged. A multivariable logistic regression model was used to predict mortality and showed that individuals with no digestive syndrome (especially the absence of oropharyngeal candidiasis), nor TB are 63% to 76% less likely to die, respectively. In addition, increases in PDW values also decreased the probability of death. Curiously, patients who were discharged showed a trend towards a concomitant increase in PDW and mean platelet volume (MPV) in relation to those who died.Conclusions: Opportunistic infections continue to be major events in morbidity and mortality of HIV/AIDS patients, and the relationship between increased PDW and the likelihood of survival suggests the need for future studies on innate immune response of platelets in HIV/AIDS inpatients.