Abstract Background and Objective: The gastric residual volume has a direct effect on the volume and timing of the subsequent feeding and causes gastric emptying and pulmonary aspiration. The present study compares the effect of Cydonia oblonga and Phyllanthus Emblica (Amla) fruit on gastric residual volume and pulmonary aspiration in mechanically- ventilated patients. Materials and Methods: This is a single-blind randomized clinical trial, including 48 patients (divided into three groups) under mechanical ventilation admitted to the intensive care unit (ICU) of Mousavi Hospital in Zanjan. Amla product and cydonia juice were gavaged in intervention groups A and, B, respectively. In all groups, the same gavage solution was prepared every three hours. Eventually, pulmonary secretion aspiration was measured (on the first, third and fifth days). Results: The difference of the mean gastric residual volume was not statistically significant in the intervention groups (on thefirst three days). The mean residual volume of the fourth and fifth days was statistically different and the rate of pulmonary aspiration in the intervention groups (on the fifth day) was significantly lower than the control group (P<0.001). The mean gastric residual volume of the two groups had no significant difference (P<0.471). Conclusion: The present study shows the effectiveness of cydonia juice and Amla on the gastric residual volume in patients admitted to ICU. The incidence of pulmonary aspiration in intervention groups has a decreasing trend (on the fifth day). Therefore, cydonia juice and Amla can be appropriate alternatives to chemical drugs. Keywords: Cydonia juice, Phyllanthus emblica (Amla) fruit, Gastric residual volume, Mechanical ventilation