Grandiose delusions have received comparatively little attention in the literature and there is limited empirical evidence assessing the efficacy of cognitive behaviour therapy for psychosis (CBTp) for individuals with grandiose beliefs. This case study presents Noah, a 23-year-old referred to our Early Intervention Service with persistent grandiose beliefs alongside other psychotic experiences. Noah received 26 sessions of CBTp. Scores on measures of perseverative thinking, delusional distress and conviction, wellbeing, and daily functioning were completed at baseline, mid-therapy, end of therapy, and at follow-up 12 weeks after the end of therapy. Results demonstrated improvement across all measures, particularly preservative thinking about beliefs. Improvement in all but one outcome was not only sustained but continued to increase at follow-up. This is one of few known reports on using CBTp with an individual with current grandiose delusions.
Highlights- (1) To explore the use of CBTp with a young male experiencing grandiose beliefs. 
- (2) To apply learning from recent research on grandiose delusions into the delivery of CBTp.