Many articles have been written on enterprise resource planning success in the last two decades in both the public and private sector. An important number of empirical studies attempt to delineate the steps of ERP project integration and their specificities. These research works can be divided into two principal phases: the implementation and the post-implementation. The complex nature of the ERP system and its implementation stages lead us to investigate about the critical success factors mentioned in both phases of integration. Recently, several studies have tried to assess the success of ERP system and highlight the CSF's based on some theoretical models. This study uses a meta-analysis methodology to highlight the principal factors leading to ERP success, and it evaluates the weight of CSF's in the process of implementing the ERP project. Based on the best studies published in the last years about ERP success, we conduct this research to determine the most important factors highly correlated with the ERP success. Eleven CSF's are identified in our meta-analysis and classified according to their significant importance based on the correlation coefficients finding in 32 articles focus only on the ERP system. Some criteria were selected to choose studies such as: Sample size, the availability of correlation coefficient finding (quantitative empirical data), the availability of reliable constructs (Cronbach's alpha), and the measurement scale of each factor.