This paper proposes a conceptual model that attempts to explain the impact of the cultural dimension of assertiveness on the perception and evaluation of a standardised advertisement. The basic concept of the model is that a given standardised advertising stimulus is likely to be perceived and evaluated differently in various cultures, dependent upon the level of importance individuals place on assertiveness (individual level assertiveness) as well as the level of assertiveness in the environment surrounding that individual (societal level assertiveness). Applying the GLOBE framework of cultural dimensions (House et al. 2004) to advertising research, consumers in the United States, Germany, Great Britain, Austria and Argentina were surveyed. Results indicate that, overall, assertiveness is a favourable cultural dimension for advertising purposes. Results demonstrate that it is not consumers from the country with the highest assertiveness scores who most positively evaluate advertisements incorporating assertive appeals. Rather, consumers from the country who perceive the highest level of assertiveness in the advertisement tend to evaluate it most positively and they, in fact, are from the country with the lowest assertiveness scores. The proposed model was confirmed to a large extent. Implications for the use of assertive appeals in international advertising are discussed and the limitations of the research are addressed.