The aim of this study was to evaluate the mid-term results of a large series of paediatric patients with long bone shaft fractures who were treated with elastic intramedullary nailing. Between November 2009 and November 2010, 108 long bone shaft fractures in 102 patients were treated with elastic intramedullary nails. The number of nails used, admission time, nail diameter/medullary canal diameter ratio of the nontraumatized extremity, weeks until radiological consolidation, weeks until full weight bearing for the femur and tibia shaft fractures, weeks until the nails were removed, number of radiographs from the diagnosis time to the removal time of nail(s), clinical complications and radiological results were recorded; the union rate, time to union, nonunion, delayed union, malrotation, malalignment, follow-up time and functional outcomes (Flynn outcome scoring) were also recorded. The mean follow-up time was 22.2 (14–30) months. The mean age of the patients was 9.6 (6–15) years for all cases. The mean nail removal time for all cases was 19.2 (17–29) weeks. Eighteen patients developed complications: six had insufficient reductions; two had refractures; four developed a deep infection; one had delayed union that needed revision; two had lower extremity length discrepancies of more than 15 mm; and three had skin impingements. The mean admission time was 19 (6–32) h; the mean number of radiographs from the diagnosis time to the removal time of nail(s) was 14 (8–20) for each fracture. All patients showed excellent or satisfactory results according to Flynn’s criteria. The mean time to full weight bearing for the femur and tibia shaft fractures was 62.4 (52–88) days. A nail diameter/medullary canal diameter ratio of over 0.4 showed good results; short union time, less lower extremity length discrepancy and less malalignment were recorded. When patients were informed about possible complications as well as the advantages, almost all chose the operative approach. According to our experience and opinion, elastic intramedullary nailing is the best choice for diaphyseal fractures in children with skeletal immaturity compared with other surgical choices such as osteosynthesis with a plate.