The purpose of this study is to assess how differences in national culture influence the impact of investments in manufacturing practices on operational performance. The paper addresses the following research question: does national culture affect the efficacy of investments in manufacturing practices? Hofstede's model of national culture is used to test whether there are operational performance differences when organisations in different cultural contexts invest in identical manufacturing practices. The research question is explored and answered by assessing the moderating role of national culture using ordinary least square analysis. The results suggest that some dimensions of national culture significantly moderate the impact of investments in manufacturing practices on manufacturing performance. This study represents a comprehensive attempt to explain differences in the impact of manufacturing practices investments on operational performance improvements in terms of cultural differences.