This dataset contains anonymised quantitative data collected as part of a randomised controlled trial evaluating the effectiveness of an Acceptance and Commitment Therapy (ACT)-based psychological intervention for surgical trainees. The study examined the impact of the intervention on psychological resilience, burnout, perceived stress, preparedness for training, and related psychological processes including self-compassion and values-based action. Participants were surgical trainees recruited from UK training programmes and randomly allocated to either an ACT-based intervention group or a comparison condition. Data were collected using validated psychometric measures at multiple time points. The dataset includes demographic variables, group allocation, and scores from the psychological outcome measures used in the study.