Self-directed bibliotherapy interventions can be effective means of psychological support for individuals with cancer, yet mixed findings as to the efficacy of these interventions indicate the need for further research. We investigated the experience of individuals with cancer after using a new self-help book, based on Acceptance and Commitment Therapy (ACT). Ten participants with cancer (nine females and one male, 40–89 years old) were given access to a bibliotherapy self-help ACT-based book and participated in post-intervention semi-structured interviews. Five themes were generated from reflexive thematic analysis: (1) The value of bibliotherapy (2) Timing is important (3) Resonating with cancer experiences (4) Tools of the book (5) ACT in action. The book was found to be acceptable (self-directed, accessible, understandable content, good responsiveness to exercises) and feasible (easy to use, ACT-consistent). Although not explicitly evaluated, participants’ reports indicated defusion, present moment awareness, and consideration of values, as the ACT processes that contributed to adjustment, via helping them to regain control over their lives and become more present within the moment. Findings also indicate that the intervention may be best accessed following completion of initial medical treatment.