In the present study, we develop a model to predict new product performance incorporating the literature on top management team (TMT) composition, trustworthiness, knowledge sharing and task reflexivity in organizations. We hypothesize that diversity and trustworthiness in the TMT should influence knowledge sharing and reflexivity and reflexivity and knowledge sharing would be positively associated with new product performance. We test the model using data collected from 39 indigenous software firms in Ireland. Results indicate that age diversity was positively related to knowledge sharing ability while educational level, tenure and functional diversity of the TMT did not have any direct effect on reflexivity or knowledge sharing ability or motivation. However, educational level of TMT, tenure and age diversity had indirect effects on reflexivity and knowledge sharing through the intervening variable of TMT trustworthiness. Further, knowledge sharing and task reflexivity had direct effects on market new product performance. Implications for research and practice are discussed.