Background: Oslo University Hospital, Norway, had by autumn 2016, accumulated a waiting list of 101 patients with obsessive-compulsive disorder (OCD) who had a legal right to receive treatment by a specialized OCD team. In this challenging situation, the Bergen OCD-team suggested to solve the problem by offering all patients an option for the rapid Bergen 4-day treatment (B4DT). The B4DT is an individual treatment delivered during four consecutive days in a group of six patients with the same number of therapists. The approach has previously shown a post-treatment response rate of 90% and a 3-month remission rate of 70%. Methods: Ninety-seven of the wait-list patients were available for the scheduled time slots, and 90 received the 4-day format during 8 days (45 patients each week). The therapists were recruited from 22 different specialized OCD-teams from all over Norway, and 44 (68%) had not previously delivered the 4-day format. Results: Post-treatment; 91.1% of the patients were classified as responders, and 72.2% were in remission. At 3-month follow-up; 84.4 were classified as responders and the remission rate was 67.7%. Oslo University Hospital now offers the 4-day treatment as standard treatment for OCD. Conclusions: We conclude that the B4DT is an acceptable and potentially effective OCD-treatment.