Objective: The goal of the research is to determine the incidence and ways in which fractures of the locomotor system occur in children and adolescents together with treatment methods applied, in order to determine which preventive actions, if any, can be taken to reduce the number of injuries among the monitored population. Methods: Frequency and fracture treatment methods in children and adolescents treated in Paediatric surgery ward in the Clinical Hospital Centre Rijeka between 01.01.1990. and 31.12.1999. have been retrospectively examined. The patients were distributed according to their age, sex and the place of residence, while the distribution of injuries was done according to the side where the injury was placed, single and multi-bone injuries, localization, the way of occurrence and the treatment method. The examined group comprises 3503 patients with injury of the locomotor system aged from 0-19 years of life. Both sexes are included being divided into the age groups as follows: 0-2 years (small children); 3-6 years (preschool age); 7-14 years (elementary school); and 15-19 years (high school). Results: The results show that the injuries are more common in male children (71%). Based on the mode of injuries occurrence it has been recorded that most children were injured while playing sports (16%). The injuries of the upper extremities are more frequent on the left upper arm and forearm and the right fist is more frequently injured than the left one. The injuries of all the segments of the lower extremities are more common on the right side. The results show that the number of patients treated operatively has been increased. According to the territorial distribution the largest number of cases come from the Primorsko-Goranska County. Discussion and conclusions: All the quoted results suggest that the skeleton injuries during the growth period are very significant, in male children especially. Majority of injuries occur in sports games, suggesting the intensified attention to construction and security of children`s sports grounds and playgrounds, and monitoring the children in sports games. From 1966 the newer surgical treatment of fractured long bones (ECMES) has been increased, following the world trends.