This study investigates how post-M&A interdepartmental integration affects the efficiency and effectiveness of new product development (NPD) The total sample size was 251 respondents Confirmatory factor analysis (CFA) and structural equation modeling (SEM) were used for statistical analysis Analytical results indicate that, although collaboration interdepartmental integration positively correlates with product vision, interaction interdepartmental interaction integration does not reach a significant level Despite the fact that some interaction is essential when developing new product competitive advantage (NPCA), such interaction does not necessarily achieve success. Further, product vision positively correlates with new product competitive advantage and NPD performance, and new product competitive advantage positively correlates with NPD performance In addition, an examination of the mediation effect in terms of Sobel t-test reveals that product vision is a significant mediator for the influence of interdepartmental integration on new product competitive advantage, while the new product competitive advantage is also a significant mediator for the influence of interdepartmental integration on NPD performance Moreover, this study provides a framework for managing post-M&A integration and closes with a discussion of the theoretical and practical implications of the research findings (C) 2010 Elsevier Inc. All rights reserved