Purpose: There is a growing emphasis on improving quality of life of people with prostate cancer. However, those undergoing active surveillance remain underrepresented in the literature with less known about their unique challenges. Therefore, we aimed to explore their lived experiences post diagnosis and its effect on their mental, social, and physical wellbeing. Methods: Qualitative semi-structured interviews were conducted with 13 men undergoing active surveillance for low-risk disease. Thematic analysis was used to inductively co-construct themes through the lens of the biopsychosocial model. Results: Mental wellbeing was strongly affected in our participants due to the overwhelming emotional impact of their diagnosis resulting in an ‘Emotional Diagnostic Disequilibrium’. Informational awareness and education about prostate cancer helped patients with ‘Recognition of the Impact’. Patients experienced an ‘Unsettling Monitoring Cycle’ due to the increased fear and anxiety around PSA monitoring appointments, with some men ignoring their mental wellbeing needs as their disease is ‘A Future Problem’. ‘Concealment of Diagnosis’ left many feeling isolated and highlighted an important coping mechanisms in the ‘Importance of a Social Support Network’ theme. Finally, physical health mostly changed through alterations in health behaviour, leading to ‘A Healthier Lifestyle’ with increasing attribution of physical symptoms to age through ‘Symptomatic Overshadowing’. Conclusion: The greatest disease impact on men’s wellbeing was at the time of diagnosis, with a subsequent cyclical anxiety and fear of disease progression prominent around monitoring appointments. Future research should explore ways to better support patients with these issues and at these times, improving their quality of life.