This study aims to assess the impact of the antecedents of Integrated Management System (IMS) implementation on the IMS maturity and its subsequent impact on operational performance in the context of Indian Small and Medium Enterprises (SMEs). Using Theory of Planned Behavior, this study develops research hypotheses linking challenges and motivation to implement IMS with IMS maturity and its impact on operational performance. Using Structural Equation Modelling to analyze the primary data collected from 144 SMEs in India, this study finds that intrinsic motivation drives firms towards higher levels of maturity while extrinsic motivation for implementation leads to lower levels of IMS maturity. This study not only empirically evaluates a comprehensive framework on IMS maturity but also contributes to growing literature on analysis of Developing Economy SMEs. The findings of this research may drive SMEs to focus on IMS maturity, as the results suggest that it is positively related to operational performance.