Background: There is a small body of research indicating that mindfulness training can be beneficial for people with distressing psychosis. What is not yet clear is whether mindfulness effects change in affect and cognition associated with voices specifically. This study examined the hypothesis that mindfulness training alone would lead to change in distress and cognition (belief conviction) in people with distressing voices. Method: Two case studies are presented. Participants experienced long-standing distressing voices. Belief conviction and distress were measured twice weekly through baseline and mindfulness intervention. Mindfulness in relation to voices was measured at the start of baseline and end of intervention. Results: Following a relatively stable baseline phase, after 2–3 weeks of mindfulness practice, belief conviction and distress fell for both participants. Both participants' mindfulness scores were higher post treatment. Conclusion: Findings show that mindfulness training has an impact on cognition and affect specifically associated with voices, and thereby beneficially alters relationship with voices.