ABSTRACT In studies of psychotherapy, researchers typically rely on symptom-focused measures to assess treatment success. However, good psychotherapy can engage clients in many other transformations–such as, improved relationships, insight, and emotional engagement. In line with research indicating that clients value a distinct set of therapeutic gains, our goal was to develop a measure that assesses the quality of psychotherapy as experienced by clients. Initial items were based upon results from an omnibus meta-analysis of the qualitative literature on clients’ experiences of therapy, lending both construct and face validity. In this initial study, exploratory (Study 1) and confirmatory (Study 2) factor analyses were conducted. The Clients’ Experiences of Therapy Scale (CETS) contains five subscales including 15 questions. It demonstrated strong test-retest reliability and inter-item consistency across diverse demographic groups and psychotherapy orientations. Comparisons with symptom measures suggested that the scale assesses related but distinct constructs. The CETS shows potential to predict client dropout from therapy, correctly classifying 80.0% of cases posthoc. When used in routine outcome monitoring, because the items assess the quality of psychotherapy in relation to in-session process and micro-outcomes, they can provide feedback to therapists, on specific in-session dynamics to change, discuss with clients, or refine in practice.