In this study, we aimed to understand how people with first-episode psychosis experienced a transdiagnostic cognitive therapy called Method of Levels (MOL). Semi-structured interviews were conducted with 12 individuals who were participants of a feasibility randomised controlled trial of MOL for first-episode psychosis. Interviews were analysed using thematic analysis. Four superordinate themes were identified: the therapist’s approach; being in control; thinking and talking; and looking at problems from a different perspective. Our findings suggest that therapy was experienced as most helpful when participants perceived themselves to have control over the process of therapy, could explore and express of a wide range of difficulties, and were able to generate new perspectives on their problems. MOL and its associated system of client-led appointment scheduling were predominantly perceived to be helpful and appear suitable for further testing in a larger clinical trial.