Day surgery is a new, modern concept of surgical treatment that involves minimally invasive surgical interventions according to a predetermined time, which last less than six hours. In pediatric surgery, the majority of procedures are related to the field of pediatric urology and orthopedics, the frequency of which is followed by the number of day surgeries. Circumcision, surgery of hydrocele and inguinal hernia, orchidopexy of undescended testicles, abdominal hernias and soft tissue surgeries are the most common procedures in the pediatric population. The aim of this paper was to show the development of one-day surgery at the Pediatric Surgery Department of the Clinical Hospital Centre in Rijeka and to provide information on the types of surgical procedures and their complications. The research included 585 procedures with 573 patients, of which 79 were girls and 506 were boys, whose average age was 7 +/- 4 years. In the examined population were predominantly male patients in the total percentage of 87%. Among the mentioned procedures the most commonly performed were circumcisions, hernioplasties, removal of bone implants and fixators, soft tissue tumors excision, orchidopexies, spermatocele surgeries and combined surgical procedures. 16% of patients developed complications, of which 2.6% were severe. The most common complications were postoperative edema after circumcision and hematoma after testicular orchidopexy. The research showed significant progress and the trend of development of this surgical model, which is becoming an increasingly necessary approach to treatment. Professional cooperation, better education and constant review with standardization of procedures are key factors to the good functioning day surgery units and quality of treatment.