This study analyzes hospitalizations due to ambulatory care-sensitive conditions with a focus on infectious and parasitic diseases (IPDs) and validates the Hospital Information System, Brazilian Unified National Health System (SIH/SUS) for recording hospitalizations due to ambulatory care-sensitive conditions in a hospital in the Federal District, Brazil, in 2012. The study estimates the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the SIH for recording hospitalizations due to ambulatory care-sensitive conditions, with the patient's medical file as the gold standard. There were 1,604 hospitalizations for hospitalizations due to ambulatory care-sensitive conditions (19.6%, 95%CI: 18.7-20.5), and the leading IPDs were renal and urinary tract infection, infection of the skin and subcutaneous tissue, and infectious gastroenteritis. IPDs were the leading cause of hospitalization in the 20 to 29-year age bracket and caused 28 deaths. Sensitivity was 70.1% (95%CI: 60.5-79.7), specificity 88.4% (95%CI: 85.6-91.2), PPV = 51.7% (95%CI: 42.7-60.7), and NPV = 94.3% (95%CI: 92.2-96.4). The findings for admissions due to ACSCs in this hospital were similar to those of other studies, featuring admissions for IPDs. The SIH/SUS database was more specific than sensitive.