This study tested a theoretical model of one mediator and four moderators of the relationships between two masculinity variables (Traditional Masculinity Ideology and Gender Role Conflict) and Attitudes toward Seeking Professional Psychological Services (Attitudes). Self-stigma was the hypothesized mediator and the hypothesized moderators were: 1) Depression, 2) General Self-efficacy, 3) Precontemplation, and 4) Barriers to Help-Seeking. A sample of 654 men responded to an online survey of 9 questionnaires. After evaluating mediation in the absence of moderation, moderated path analyses were conducted for each moderator. The relationship between Traditional Masculinity Ideology and Attitudes was partially mediated by Self-stigma, whereas that between Gender Role Conflict and Attitudes was completely mediated. No indirect or direct paths involving Gender Role Conflict were moderated by any moderators. Both Depression and Barriers to Help-Seeking moderated both stage 1 (the path from Traditional Masculinity Ideology to Self-stigma) of the mediated relationships and the direct effects between Traditional Masculinity Ideology and Attitudes. Pre-contemplation moderated the direct effect between Traditional Masculinity Ideology and Attitudes. The findings suggest that the relationships between masculinity variables and men’s negative help-seeking attitudes may be better understood through their relationships with other variables that serve as mediators and moderators. Findings from the present study may offer some direction in the design of interventions to remediate men’s negative help-seeking attitudes.