In this study, we aimed to understand how people with first-episode psychosis experienced a transdiagnostic cognitive therapy called method of levels (MOL). Semistructured interviews were conducted with 12 individuals who were participants of a feasibility randomized controlled trial of MOL for first-episode psychosis. Interviews were analysed using thematic analysis. Four superordinate themes were identified: ‘The therapist's approach’; ‘I was 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 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.