This paper studies the effects of four beliefs of a group of end users on the adoption of ERP systems. The beliefs examined were perceived usefulness, ease of use, expected capability, and expected value. A sample of 58 SAP users was collected, via online survey, from a large company in Saudi Arabia. The validity and the reliability of the data collection instrument were tested using the exploratory factor analysis and Cronbach's Alpha coefficients, respectively. Using multiple regression analysis, the perceived ease of use and the expected value of ERP system was found to have a significant direct effect on the acceptance of ERP system. However, the perceived usefulness and expected capability did not have a direct significant effect on acceptance of ERP systems. The study provides insights for organizations implementing ERP systems in developing countries.