Supracondylar fractures represent the most frequent cause of pediatric elbow injuries, at 64%, in children under eight years old. These fractures can present complications such as: A) Complications prior to treatment: 1) neurological, 2) vascular and 3) compartment syndrome. B) Complications after treatment: 1) early, in the first days after treatment: loss of reduction, neurological, vascular, compartment syndrome, infection of Kirschner wires. 2) Late complications in treatment: Angular deformity, loss of mobility, ossifying myositis, avascular necrosis of the trochlea, others.To determine the frequency of complications in humeral supracondylar fractures in less than eight years.A retrospective, observational cohort study was conducted in patients under 8 years of age during the period of March 2014 to February 2018.277 patients were obtained with the following percentages: cubitus varus 3.97%, neurological lesions prior to surgical treatment 1.44%, early neurological complications to treatment 1.44%, infections of Kirschner needles 0.72%, cubitus valgus 0.72%, loss of mobility 0.36%.The most common complication of humerus supracondylar fractures in this study was cubitus varus and neurological complications prior to treatment.