Introduction. Diaphyseal forearm fractures constitute the second most numerous group of injuries to the locomotor system in children, right after the injuries of the distal part of forearm bones. Most often, diaphyseal forearm fractures in children occur through an indirect mechanism. In the treatment of diaphyseal forearm fractures in children, the aim is to achieve union, correct length and axis of both forearm bones. Diaphyseal forearm fractures can be treated non-surgically, using a cast, and surgically. In children, the most frequently used surgical method is closed reposition and intramedullary stabilization with the use of TEN nailing. During treatment, possible complications must be taken into account. Objective. The objective of the study is to analyse the most common late complications of diaphyseal forearm fractures in children in relation to the treatment method. Materials and methods. The study included 126 children aged 5-17 (mean age 11.4) hospitalized due to diaphyseal forearm fractures at the Department of Children’s Orthopaedics and Rehabilitation of the Medical University of Lublin between 2015-2021. All patients were qualified for closed osteosynthesis and stabilization using elastic intramedullary nailing according to the Metaizeau technique. The analysis covered the type and incidence of complications up to six months after removing the fixation, in relation to the method of surgical treatment. Results. The analysed group of patients at developmental age consisted of 126 patients, 26 girls and 100 boys. All children were qualified for surgical treatment using elastic intramedullary stabilization according to Metaizeau. Of all the patients, 120 patients experienced no complications, 5 patients experienced refractures, and 1 patient had delayed union. Non-union was not observed when using this method, and refracture turned out to be the most common complication. Complications of surgical treatment in one patient were treated non-surgically, and five patients were qualified for intramedullary restabilization. Every twentieth child developed a form of complication. Conclusions. Surgical treatment of diaphyseal forearm fractures using the Metaizeau technique in children carries a very low rate of complications.