Enterprise resource planning (ERP) has become a necessary in many organizations and many business units have been trying to emerge into an integrated system. There are many advantages on having an efficient ERP but many corporations fail to reach a full operational ERP for many reasons. In this paper, we present an empirical investigation to find important factors influencing ERP implementation in one of the biggest Iranian automakers named Iran Khodro. The proposed study designs a questionnaire in Likert scale consists of 46 questions, distributes it among some managers in this firm. Cronbach alpha is calculated as 0.802. In addition, Kaiser-Meyer-Olkin Measure of Sampling Adequacy and Approx. Chi-Square are 0.788 and 1677.307, respectively. Based on the results of our survey, we have derived eight factors including intelligence information, customer comfort, structure oriented, resource management, process oriented, customer oriented, flexible structure and knowledge management