The article theoretically proposes and empirically tests an individual and national–cultural nomological network of consumer involvement. A consumer survey in the United Kingdom, France, Germany, Spain, and Italy captures nomological network data. Findings are significant in three areas. First, the empirical study provides evidence for the cultural invariance of the measurement of consumer involvement. Second, results determine the mediating nature of individual-level consumer involvement. The nomological network differentiates between the antecedent role of cognitive involvement and the subsequent affective involvement state with explanatory effect on brand commitment and brand experimentation. Third, the study identifies the moderating role that uncertainty avoidance and masculinity/femininity play on the involvement relationships. The article concludes by discussing the theoretical implications for the impact of individual and national–cultural variables on the activation and sources of consumer involvement. © 2007 Wiley Periodicals, Inc.