Despite the growth of school counselling in the UK, very few studies have examined its effectiveness. As part of a wider evaluation of the work of the NSPCC Schools Counselling Project, 219 pupils aged 11-17 years completed the TEEN CORE questionnaire before receiving counselling; 104 of these pupils also completed a questionnaire after counselling and a further 29 also completed a questionnaire three months after the end of counselling. The study found that the mean TEEN CORE score after counselling was significantly lower compared to the mean score before counselling, indicating fewer problems/less distress. Analysis of the data collected after three months (n=29) suggests that this treatment gain was maintained at follow-up. This is evidence to suggest that school counselling is effective, but this paper argues that further research is needed to identify when and for whom it is most effective. (Contains 5 tables, 2 figures, and 2 notes.)