Background: Of the life-threatening conditions for critically ill patients are to have intra-abdominal hypertension (IAH) and abdominal compartment syndrome (ACS). Teaching of nurses is the first line of defense that benefits patients and prevent access to complications. Aim: This paper was aimed to evaluate the effect of teaching program about ACS on (1) nurses’ knowledge and skills and (2) development of ACS among critically ill patients. Design and methods: A quasi experimental research design was used. Convenience sampling of 32 nurses working in General and Trauma ICUs and two groups of patients (pre-teaching patients =20) and (post teaching patients=25) were included in the study. All nurses were evaluated pre and post teach program for their knowledge and skills. Along with, all patients were evaluated for development of acute compartment syndrome for two consecutive months. The study took approximately eight months. Results: nurses’ knowledge and skills about ACS improved significantly after implementing teaching program (p= 0.001). Development of ACS was identified in 20% of preteaching patients versus none of post teaching patients. Mean score of IAP was significantly higher among preteaching than post teaching patients on fifth day (p=0.003**). Conclusion: teaching is important to clarify, remind, and master nurses' knowledge and skills. Highlighting the importance of monitoring IAP of most vulnerable patients help to early detection of IAH and prevent access to ACS.