Increased social self-esteem (SSE) was explored as an explanation of the persuasive effectiveness of nationalistic advertisements for nationalistic subjects. Psychology I students. volunteering on the basis of feeling either “Australian” or 'non-Australian” (n = 56 for both; average age 20.1 years, 60 female, 52 male) were exposed to either three nationalistic or three non-nationalistic advertisements. A newly developed SSE questionnaire was administered either prior to or following advertisement viewing. Nationalistic advertisements were persuasive for Australian subjects, but not with non-Australian subjects. Although the SSE of Australian subjects exposed to nationalistic advertisements did not increase, these subjects did not suffer the decline in SSE shown by nationalistic subjects exposed to non-nationalistic advertisements. Viewing nationalistic advertisements therefore “protected” the SSE of nationalistic subjects from a decline which occurs following advertisement exposure. Findings were related to Cohen's (1959) view concerning differential persuasibility of high and low self-esteem subjects. and to the view of Lasch (1978) and others that advertising “fosters self-denigration and self-contempt”.