OBJECTIVE. "Motivational interviewing" (MI) has shown to be broadly applicable in the management of behavioural problems and diseases. Only a few studies have evaluated the effect of MI on type 2 diabetes treatment and none has explored the effect of MI on target-driven intensive treatment. METHODS. Patients were cluster-randomized by GPs, who were randomized to training in MI or not. Both groups received training in target-driven intensive treatment of type 2 diabetes. The intervention consisted of a 1½-day residential course in MI with half-day follow-up twice during the first year. Blood samples, case record forms, national registry files, and validated questionnaires from patients were obtained. RESULTS. After one year significantly improved metabolic status measured by HbA1c (p < 0.01) was achieved in both groups. There was no difference between groups. Medication adherence was close to 100% within both treatment groups. GPs in the intervention group did not use more than an average of 1.7 out of three possible MI consultations. CONCLUSION. The study found no effect of MI on metabolic status or on adherence of medication in people with screen detected type 2 diabetes. However, there was a significantly improved metabolic status and excellent medication adherence after one year within both study groups. An explanation may be that GPs in the control group may have taken up core elements of MI, and that GPs trained in MI used less than two out of three planned MI consultations. The five-year follow-up of this study will reveal whether MI has an effect over a longer period.