Mental health of undergraduate students is receiving more attention because of the increase in the prevalence and intensity of psychological distress. Our aim is to verify the effectiveness of a cognitive behavioural counselling service in reducing psychological distress and improving academic self-efficacy in a sample of 124 students (57% above the clinical cut-off) using a pre-post assessment design. Data show a significant reduction of distress and symptoms scores among students who completed the intervention and half of them had a reliable change. Preliminary data also show a significant improvement in academic self-efficacy. University counselling services represent common first-line services for students and are effective in treating psychological distress in a wide range of clinical and sub-clinical situations.