<p>Given the importance of analyzing the impacts of advertising persuasion, the general objective of this study has been to study the relationship between assertiveness and mechanisms of resistance to advertising persuasion. To this end, 403 subjects between the ages of 18 and 70 participated in this study (X = 22.87; DT = 15.3). It has been proven that the young adult group obtained the highest scores in assertiveness and psychological reactance. In terms of gender, women presented more assertive behaviors and men more psychological reactance. The results of the study show that the level of studies turned out to be a statistically non- significant variable and that the work situation is only statistically significant for the assertiveness scale. It is also shown that the Internet is the most influential advertising source.</p>