User reluctance or unwillingness to adopt or use the newly implemented ERP system is often cited as one of the main reasons for ERP failures. To examine important antecedents leading to the lack of user acceptance towards the implemented ERP systems, this research reviewed the literature related to ERP adoption by users, developed hypotheses to explain ERP user acceptance, and conduct a survey to test the hypotheses. This research adapted the ERP acceptance model developed by Nan, et. al. (2004) and included five more constructs as the antecedents of ERP adoption. These new added variables are related to individual characteristics and the organizational contexts in which the ERP implementation takes place. Nine constructs comprises of ERP Ease of Use, ERP Usefulness, ERP Compatibility, ERP Business Fit, Shared Belief in The Benefit of ERP System, Facilitating Condition, ERP Self-Efficacy, Argument for Change and Personal Innovativeness of IT were hypothesized as antecedents to ERP systems symbolic adoption. This research uses 176 data set from several divisions of an Indonesian telecommunication company (Telco). Using structural equation modeling analysis, the result from the examined questionnaire shows that ERP Compatibility and Attitude Toward ERP System Use have direct effects on ERP Symbolic Adoption, while ERP Business Fit and ERP Usefulness influences ERP Symbolic Adoption by being fully mediated through Attitude.