Traumatic primary anterior shoulder dislocation has a very high recurrence rate among young people. This has supplied the motivation for studies to find methods of treatment that might become an alternative to traditional therapy. A prospective controlled study was performed to test the hypothesis that acute arthroscopic lavage might have a positive effect on recurrence rate as well as on shoulder stability, range of motion and mobilization. 30 consecutive patients between 18 and 30 years of age were randomized into 2 groups, 1 control group treated conservatively and 1 group treated with acute arthroscopic lavage within 10 days. Clinical examination was made by an independent observer at 1, 6 and 12 months. Results at 6- and 12-month check-ups showed a statistically significantly lower rate of redislocation and a wider range of motion for the group treated with acute arthroscopic lavage. Functional assessment according to the Lysholm shoulder score also indicated better functioning of the joint. Our 1-year follow-up shows very promising and interesting results.