Background: There is limited research on the applicability and effectiveness of Acceptance and Commitment Therapy (ACT) for people experiencing psychotic disorders. Clinical trials suggest ACT may be efficacious in reducing distress and rehospitalization rates in psychosis. Mindfulness and reduced literal believability of thought content have been associated with reduced distress for this population. Aims: To better understand ACT for psychosis, this study investigated clients’ perspectives of the hypothesized active therapeutic processes of ACT. Method: Semi‑structured interviews, conducted with nine adults diagnosed with schizophrenia or schizoaffective disorder and persistent positive symptoms, were analysed thematically. Results: Four themes emerged: Usefulness of therapy; Changes attributed to ACT; Understanding of therapy; and Non-specific therapy factors. All participants found therapy useful and recommended ACT. Mindfulness, defusion, acceptance and values work were described as the most useful therapy components and contributing to positive changes. Self-rated frequency of symptoms did not change; however a reduction in the intensity and distress associated with symptoms was reported. Non-specific therapy factors were deemed useful by participants but not directly related to outcome. Conclusions: These findings are consistent with the theoretically defined underlying active processes of ACT and are relevant for this population. The findings also indicate important clinical implications for ACT for this client group: greater attention to the client connecting metaphors and concepts to the intended meaning may be valuable; caution should be used with some mindfulness and defusion techniques for intense experiences; and values work may be particularly useful for this population.