The first chapter of this thesis is a systematic literature review that examined the psychological impact of an interpersonal betrayal on men’s mental health. It is well known that men in general may express mental health difficulties differently from women and due to a general reluctance in men to discuss their emotional problems, men may therefore be prone to shame. As shame is a key feature of betrayal trauma, it was expected that men may experience self-criticism and shame in response to betrayal, compounded by the increased risk of experiencing shame in response to emotional problems in general. A narrative synthesis of eight studies that varied in methodological design indicated a range of negative psychological outcomes that men reported from a betrayal by a trusted other. The findings provided evidence of men experiencing some degree of distress; however, the nature and severity of this distress is not wholly clear and requires further investigation. Further exploration of gender differences is recommended to inform appropriate intervention.The second chapter of this thesis is an empirical study that investigated the impact of a brief compassion intervention compared with guided relaxation in men that have been interpersonally betrayed. In total, 52 men participated with 26 randomised into each group. The study employed a 2 x 3 design using two conditions (compassionate-imagery and relaxation) tested at three time points (pre, post and one-week follow-up). Results showed an effect of time on scores but no differences between compassion and relaxation. Specifically, this study’s findings demonstrated preliminary evidence of efficacy with both brief compassionate imagery and guided relaxation for improving positive mood, reducing negative mood, and increasing betrayed men’s motivation to act in ways that alleviate suffering. Further research is warranted to understand the mechanisms of change involved so that psychologists can effectively meet men’s emotional needs.