The Stanford Chronic Pain Self-Management Programme (CPSMP) consists of 6 2½-hour weekly workshops focusing on how to manage pain in daily life. The workshops are facilitated by 2 workshop leaders of whom at least 1 must suffer from a long-term pain condition. The program is highly structured and manualized. Only few controlled trials testing the effect of CPSMP exist. Enrolled in the study were 424 adults from 19 Danish municipalities, (72% women; age: 25-93 years) with pain of any etiology and great variation in pain history (0-50 yrs). Of these, 216 were randomized to a lay-led version of the CPSMP. The primary outcome was pain-related disability. Secondary outcomes were pain, pain catastrophizing, self-efficacy, emotional distress, physical symptoms, and illness worry. Outcomes were measured before randomization, immediately after the CPSMP (response rate: 94%), and at 3-month follow-up (response rate: 92%). National register data on health expenditure were obtained to examine effects on health care use. ClinicalTrials.gov Identifier: NCT01306747. The CPSMP had no effect on the primary outcome pain-related disability or on health expenditure during intervention and follow-up period. Small positive effects on emotional distress and illness worry 3 months after CPSMP were observed. Lay-led CPSMP is not recommended as treatment for chronic pain-related disability. This heterogeneous group of patients with pain did not benefit from the CPSMP except for a small, but clinically insignificant improvement in psychological well-being.