Antibiotic overuse and the resulting antimicrobial resistance pose significant global public health challenges, providing an avenue for opportunistic pathogens like Acinetobacter baumannii to thrive. This study will report the trends of Acinetobacter baumannii antimicrobial resistance patterns at the Hospital Teodoro Maldonado Carbo, Ecuador. An observational, analytical, longitudinal, and prospective study was conducted involving patients diagnosed with hospital-acquired infections. Antimicrobial susceptibility testing was performed, followed by molecular analysis of carbapenemase genes in Acinetobacter baumannii isolates. We included 180 patients aged from 16 to 93 years. The hospital mortality rate was 63/180 (35%). Invasive mechanical ventilation (IMV) was indicated in 91/180 patients (50.4%). The overall survival (OS) rate in patients on IMV was 49.5% (45/91), with a median survival of 65 days. The OS rate in patients not on IMV was 80.9% (72/89), with a median survival of 106 days (HR 2.094; 95% CI 1.174–3.737; p = 0.012). From multivariate analysis, we conclude that ventilator-associated pneumonia is the most related factor to OS.