We investigate the moderating role of national openness to foreign markets on consumer responses (attitude to ad, brand and purchase intention) to different degrees of advertising adaptation in Belgium, Iran and India. We operationalize three levels of advertising adaptation (standardization, glocalization and adaptation) by manipulating the model (international versus local celebrity) and advertising copy (international versus local advertising copy). The results show that societies with a low openness to foreign markets respond more positively to fully adapted ads than to glocalized and standardized ads. The differences in responses decrease with national openness. level characteristics, the environmental country-level variable of 'national openness to foreign markets' has a predictive capability for consumer responses to advertising adaptation. National openness to foreign markets is an environmental measure of the extent of a nation's economic, social and political contact with foreign societies, in other words the extent of its globalization. It depends on several environmental factors such as worldwide investments, production, marketing, advances in telecommunication technologies, the Internet, increase in world travel and growth of global media (Alden, Steenkamp and Batra 2006; Dreher, Gaston and Martens 2008; Özsomer and Simonin 2004). To the best of our knowledge, the relationship between a country's openness to foreign markets and consumer responses to different degrees of advertising adaptation is an unexplored research topic. Additionally, this factor is relevant for international advertising practice, and specific measures for this 'openness' variable are publicly available, and thus easy to use by international marketers. Second, previous experimental studies on advertising adaptation have largely ignored the option of a hybrid, glocalization strategy, by comparing only the two extremes of advertising adaptation vs. standardization (Hornikx and O'Keefe 2009; Wei and Yu 2012). Glocalization is a semi-adaptation strategy that tries to combine the advantages of both standardization and adaptation strategies (Roberts and Ko 2001). Many authors advocate in favor of a glocalization strategy as the key for better communication with consumers with different cultural backgrounds (e.g., Matusitz 2010; Sinclair and Wilken 2009). In the present study, the degree of advertising adaptation is operationalized at three levels (i.e., standardization, glocalization, and adaptation) by means of two widely used executional elements, the origin of the (celebrity) model as a visual cue, and language, geographical locations and web domain as advertising copy. The present study was conducted among consumers in three countries with different levels of openness to foreign markets: Belgium (high openness), India (moderate openness) and Iran (low