Purpose – The purpose of this paper is to explore the quality of interactions among new product development team members, wherein functional diversity, team stability, and transactive memory system are antecedents of teamwork quality. Three measures of outcomes are used (team learning, speed to market, product success), and task complexity is a moderating variable. Design/methodology/approach – A theoretical model was developed and tested on the survey data collected from 93 product managers of Turkish companies. The product managers who participated in this study represented various industries including those of telecommunications, food, material, software, machinery, chemicals, and service technologies. Findings – An inverted-U impact of both functional diversity and team stability on teamwork quality was found, and a positive impact of transactive memory system on teamwork quality. Teamwork quality was significantly related to improved performance, and task complexity moderates this relationship. Originality/value – The paper is the first attempt to explore the role antecedents and its outcomes in NPD teams.