62 children, younger than sixteen years of age, with an evident or suspected acute patellar dislocation in 64 knees admitted to the emergency department, were randomized to be treated non-operatively or operatively. This study aimed to compare the long-term outcomes between treatments. Overall, the long-term subjective and functional outcomes after acute patellar dislocation were reported satisfactory in majority of the patients at the 14 year follow-up. Despite a very high rate of recurrent instability, the initial operative repair of the medial structures combined with lateral release was not found to improve the long-term outcomes.