The aim of this study was to evaluate the effect of modifying the cuff on preventing ventilator-associated pneumonia (VAP). PubMed, Embase and Cochrane Library were systematically searched from inception to April 2022, for randomised controlled trials (RCTs) that compared the effect of a new type of cuff intubation with traditional cuff intubation on VAP incidence and intensive-care unit (ICU) mortality in mechanically ventilated patients. Nine RCTs with 1937 patients were finally evaluated. The pooled results for the incidence of VAP showed that the modified cuff significantly decreased the morbidity of VAP compared with the traditional cuff (relative ratio (RR) = 0.73, 95% confidence interval (CI) 0.56-0.95, p = 0.02). The subgroup analysis revealed that polyurethane (PU) cuff (RR = 0.82, 95% CI 0.46-1.48, p = 0.52), conical cuff (RR = 0.97, 95% CI 0.73-1.28, p = 0.82) and PU-conical cuff (RR = 1.36, 95% CI 0.85-2.18, p = 0.20) did not decrease the incidence of VAP. Moreover, the improved cuff combined with subglottic secretion drainage (SSD) could significantly reduce the VAP incidence (RR = 0.58, 95% CI 0.44-0.77, p = 0.0001). In terms of ICU mortality, there was no statistically significant difference (RR = 0.83, 95% CI 0.68-1.02, p = 0.08) between the two groups. The modified cuff is superior to the traditional cuff in VAP prevention. In particular, the modified cuff combined with subglottic secretion drainage has more advantages. Key Words: Ventilator-associated pneumonia, Intubation, Endotracheal cuff, Intensive care unit, Meta-analysis.