Background: The literature places the occurrence of paediatric Monteggia lesions between 1.5% and 3% of all childhood elbow injuries. There are circumstances, which may make early correct diagnosis difficult. Failure to make an early correct diagnosis may have catastrophic consequences on joint range of motion in the chronic stage. The goal of this paper is to describe our three-step approach to the treatment of acute Monteggia lesions based on the stability and radiological appearance of the fracture dislocation, to give an overview of possible pitfalls and clinical and radiological signs that aid the diagnostic process. Methods: Retrospective analysis of 23 patients treated for this type of injury at our Department over a period of 6 years was performed. Treatment options were 1. Closed reduction under image intensifier followed by immobilization in over the elbow cast, 2. Open reduction and intramedullary nailing with ESIN, or 3. Open reduction and plate osteosynthesis. Average follow-up was 37 months. In our Department we aim for definitive treatment of fracture-dislocations in children within the acute setting. In the 23 acute cases, the selected procedure-reduction + casting/reduction + ESIN/reduction + plating-was performed within 2 to 16 h of arrival. 10 patients were treated with reduction + casting, 10 with reduction + ESIN and 3 with reduction + plating. Results: 21 patients were available for long-term follow-up. No nerve or tendon injuries or infections were observed in these cases. By managing the patients with the Three Step Method retaining the reduction was successful in all but one of our acute cases in the study period. Excellent range of motion was observed in all three groups. Conclusions: The Three Step Method allows for primary definitive treatment of these lesions with low complication rates and good range of motion result. Implementing the three step method in the acute phase helps avoid catastrophic consequences on joint range of motion in the chronic stage.