Objective To determine the risk factors for overt aspiration in adult ICU patients and to provide reference for identifying the high-risk patient and reducing overt aspiration.Methods A total of 798 adult ICU patients were selected.Univariate analysis and logistic regression analysis were performed to identify the risk factors for overt aspiration.Results The incidence of overt aspiration was 16.9%.Mechanical ventilation, gastric residual volume, intra-abdominal pressure, aspiration history and vomiting were risk factors for overt aspiration in adult ICU patients (all P＜0.05).Conclusion Adult ICU patients are at risk for overt aspiration.Attention should be paid to those with mechanical ventilation, aspiration history and vomiting, and interventions should be taken to reduce gastric residual volume and intra-abdominal pressure, thus to decrease overt aspiration.