Background: Providing nutrition to seriously unwell patients in the Intensive Care Unit (ICU) is a crucial and complex aspect of their care. It is believed that abdominal massage will stop the distention, vomiting, and reducing residual gastric volume. Aim: To identify the effect of abdominal massage on enteral nutrition tolerance among patients on mechanical ventilation. Design: To accomplish the goal of this study, quasi-experimental research design (study and control group) was used. Setting: This study was carried out in the critical care unit of Benha University Hospital in Qalyoubia, Egypt. Subjects: A purposive sample of 80 patients on mechanical ventilation who were divided into study & control (40 for each one). Three tools were used to collect the data, tool I: Patients personal and medical data. Tool II: Abdominal massage technique. Tool III: Enteral nutrition assessment. Results: Compared to the control patients, a gastric residual was found at the conclusion of the monitoring days. On the sixth day, only 7.5% of the study group had gastric residual, with a mean volume of 3.1 ml. In contrast, 52.5% of the control group had gastric residual, with a mean volume of 25.6 ml, demonstrating a highly significant difference at p value <0.01. At the end of the fourth and fifth days, distention and defecation showed extremely significant differences between the study and control groups, with p-values of 0.01**. However, there was only a slight difference related to vomiting, with a p-value of <0.05*. Conclusion: According to this study, abdominal massage for patients on mechanical ventilation decreased vomiting, abdominal distension, and gastric residual volume. Improve the frequency of defecations as well. Recommendation: Provide specialized training about abdominal massage technique to healthcare staff, including nurses and physiotherapists and replication of the study on a larger probability sample from different geographical distribution.