With improvements in detection and treatment of prostate cancer (PCa), more men than ever are living with side effects from PCa treatment; most distressingly, treatment side effects include problems with sexual functioning (e.g. erectile dysfunction, climacturia, inorgasmia). This study aims to develop a mindfulness-based group treatment for couples with sexual functioning complaints post-PCa treatment. Couples will be invited to a four-session mindfulness-based treatment group. Pre- and post-treatment outcomes (e.g., distress, sexual functioning/enjoyment, relationship satisfaction, treatment adherence) will assess feasibility and effectiveness of this novel treatment for couple's sexual lives after PCa.