Aim: The purpose of this study was to replicate and extend a pilot evaluation of the effectiveness of school-based humanistic counselling for psychological distress in young people. Method: Data were available on 32 young people who were randomised to either school-based humanistic counselling or waiting list conditions for one school term. The primary outcome measure was of psychological distress using the Young Person’s CORE (YP-CORE), at six and 12 weeks post-assessment. Secondary measures at these time-points were of psychological difficulties, self-esteem, levels of depression, and attainment of personal goals; with longitudinal evaluation of outcomes at six months post-assessment. Results: On the primary outcome measure, participants who received counselling were significantly less distressed at six weeks than those in the waiting list group but not at 12 weeks, with effect sizes (Cohen’s d) of 0.59 and 0.39 respectively. Reductions in psychological distress were maintained at followup. Discussion: Although the present findings, in isolation, are equivocal, they contribute to a body of evidence that supports the effectiveness of school-based humanistic counselling. However, the principal lesson learnt from this study was the need for rigorous training of researchers, counsellors and pastoral care teachers to ensure adherence to protocols.