Background: Some rectal cancer patients refuse or delay curative treatment despite clear evidence of benefit. Existing literature is largely quantitative and offers limited insight into the personal reasoning behind refusal, particularly within publicly funded healthcare systems. This study explores how patients understand and justify decisions to decline rectal cancer treatment. Methods: An exploratory qualitative study using semi-structured interviews was conducted with Western Australian patients who refused or substantially delayed curative-intent treatment. Interviews were recorded, transcribed, and analysed inductively using reflexive thematic analysis. Ethical approval was obtained. Results: Nine participants were interviewed. Treatment refusal was described as an active, intentional process grounded in autonomy, personal values, and a desire for control. Participants viewed themselves as independent decision makers who carefully weighed risks, benefits, and consequences. Clear, respectful communication was highly valued. Cancer nurses were seen as trusted supports. Participants also sought information from online communities, personal networks, and independent research, reinforcing confidence in their decisions. Emotional responses were substantial. Fear of major pelvic surgery, concerns about permanent stoma formation, anticipated functional changes, and the confronting nature of invasive treatment strongly shaped decisions. Many struggled to reconcile an asymptomatic diagnosis with the prospect of life-altering surgery. Conclusion: Refusal of rectal cancer treatment reflects informed, value-based reasoning rather than consequence of misunderstanding. Fear of surgery and stoma-related life changes is a major barrier that clinicians may underestimate. Enhancing communication, addressing functional outcomes transparently, and supporting autonomy may improve engagement, maintain follow-up, and create opportunities for later treatment reconsideration. Tailored decision-support strategies should be integrated into colorectal multidisciplinary care.