Using subjects from Korea and the United States, this study reports the results of an experiment designed to discover links between national culture, self-construals, and the effectiveness of comparative advertising. First, the effect of national culture on comparative advertising effectiveness was investigated. Then, using self-consttuals as individuaJlevel variables in a path model, the study investigated their mediating effects on the influence of national culture on the effectiveness of comparative advertising. Results indicated not only that national culture influences tbe effectiveness of comparative advertising, but also that self-construals have mediating effects on attitudes toward the advertisement (A ) for both indirect comparative advertising and noncomparative advertising. Thus, the study goes beyond the post hoc explanations that so many studies have used to link differences in the effectiveness of advertising to cultural variability, and thereby contributes to theory on the mediating effects of self-construals. The findings also have implications for advertising managerial practices and public policy on the regulation of advertising. But pethaps the main conttibution of the study is a research design using self-construals to demonstrate how individual-level variables can mediate the influence of national culture on advertising effectiveness., ,Despite differences in the use of comparative advertising from country co country, little research has been done to explain or predict the differences in the cross-cultural effectiveness of comparative advertising. The purpose of this study was to investigate such differences by conducting an experiment in Korea and the United States on possible links between national culture, individual-level values, and the effectiveness of comparative advertising.Comparative advertising is commonplace in the United States, but it is not widely used in most other countries, due to cultural norms or government regulation (Kotabe and Helsen 1998). In Korea, where confrontation is avoided and harmony is sought, cultural norms are inconsistent with the tactics used in comparative advertising (de Mooij 1998; Miracle and Choi 1997). Comparative advertising has been allowed officially in Korea only since 2001, and has not been widely used.Korea and the United States seemed to be a logical pair of countries for this study for two reasons: (1) the sharp contrast in the use of comparative advertising in Korea and the United States, and (2) the extreme cultural differences between the two countries. Hofstede(1991) reported that Korea is a highly collectivistic country with a low individualism rank (43rd Yung Kyun Choi (Ph.D., Michigan State University) is an assistant professor in the Department of Advertising, Dongguk University. out of the 53 countries and regions studied) and a low individualism score (18 in the range of 6 to 91). In contrast, the United States is the most individualistic and least collectivist of the 53 countries and regions studied (ranking number 1, ...