Acinetobacter baumannii is a major cause of ventilator-associated pneumonia (VAP). The high resistance of this bacterium to antibiotics makes its control and treatment difficult. This study aimed to investigate the prevalence of multidrug-resistant (MDR) A. baumannii isolated from patients with VAP. Indexed articles in international databases on MDR A. baumannii isolated from patients with VAP were reviewed in a period from 2011 to 2020. Articles with full text in English were included and review articles, abstracts, and articles in languages other than English were excluded from the study. A random effect model using Meta R software, version 2.13 with a 95% confidence interval (CI) was used for data analysis. The final prevalence of A. baumannii isolated from patients with VAP in the above-mentioned period was 0.38 (95% CI: 0.26–0.52). Higher and lower prevalence rates were observed in Asia (0.43 (95% CI: 0.42−0.44)) and Africa (0.10 (95% CI: 0.07−0.12)), respectively. The overall prevalence rates of MDR, extensively drug-resistant (XDR), and pan drug-resistant bacteria (PDR) A. baumannii were reported as 0.71 (95% CI: 0.59−0.81), 0.73 (95% CI: 0.52−0.90), and 0.40 (95% CI: 0.28−0.52), respectively. The total prevalence of A. baumannii in males (0.57 (95% CI: 0.48−0.65)) was higher than the prevalence in females (0.35 (95% CI: 0.28−0.42)). VAP was directly related to different years, continents, drug resistance, and gender (P < 0.0001). VAP has particular importance in the intensive care unit (ICU) and having standards for infection control as well as proper use of antibiotics is essential for the prevention of MDR A. baumannii.