The use of enterprise resource planning (ERP) systems has grown enormously since 1990, but the failure to completely learn how to use them continues to produce disappointing results. Today's rapidly changing business environment and the integrative applications of ERP systems force users to continuously learn new skills after ERP implementation. This study explores the effects of post-implementation learning on ERP usage and ERP impact and identifies the factors that can impact post-implementation learning, such as social capital and post-training self-efficacy. This study employs a survey method to examine the perceptions of ERP users. The theoretical model is tested by using structural equation modelling on a dataset of 812 users. This study finds that post-implementation learning has a significant positive effect on ERP usage and ERP impact, and that social capital and post-training self-efficacy are important antecedent factors of post-implementation learning. Post-training self-efficacy also significantly affects ERP usage and ERP impact. The implications for research, practice and future research directions are discussed. (Contains 1 table and 2 figures.)