Three-dimensional (3D) printing technology is increasingly being utilized in various surgical specialities. In paediatric orthopaedics it has been applied in the pre-operative and intra-operative stages, allowing complex deformities to be replicated and patient-specific instrumentation to be used. This systematic review analyses the literature on the effect of 3D printing on paediatric orthopaedic osteotomy outcomes. A systematic review of several databases was conducted according to PRISMA guidelines. Studies evaluating the use of 3D printing technology in orthopaedic osteotomy procedures in children (aged ≤ 16 years) were included. Spinal and bone tumour surgery were excluded. Data extracted included demographics, disease pathology, target bone, type of technology, imaging modality used, qualitative/quantitative outcomes and follow-up. Articles were further categorized as either ‘pre-operative’ or ‘intra-operative’ applications of the technology. Twenty-two articles fitting the inclusion criteria were included. The reported studies included 212 patients. There were five articles of level of evidence 3 and 17 level 4. A large variety of outcomes were reported with the most commonly used being operating time, fluoroscopic exposure and intra-operative blood loss. A significant difference in operative time, fluoroscopic exposure, blood loss and angular correction was found in the ‘intra-operative’ application group. No significant difference was found in the ‘pre-operative’ category. Despite a relatively low evidence base pool of studies, our aggregate data demonstrate a benefit of 3D printing technology in various deformity correction applications, especially when used in the ‘intra-operative’ setting. Further research including paediatric-specific core outcomes is required to determine the potential benefit of this novel addition. Cite this article: EFORT Open Rev 2021;6:130-138. DOI: 10.1302/2058-5241.6.200092