Background: Childhood injuries are the leading cause of death and disability for children over the age of one-year, supracondylar fractures are the most common type of elbow fractures that responsible for hospital admission in children. A totally displaced fracture is one of the most difficult fractures to manage either closed or open reduction and pinning, the aim of this study is to study the outcome and associated factors of this fracture when treated with open reduction and pinning. Objective: to determine outcome and associated factors of supracondylar humeral fracture in children treated with open reduction and pinning in Tibebe Ghion and Felege Hiwot comprehensive specialized hospital, Bahir Dar, North west Ethiopia from January 2022 to June 2023 Methods: A cross-sectional study design was used to conduct the study on patients admitted at TGSH and FHCSH on Orthopedic ward and who get orthopedic surgical care from January 2022 to June 31, 2023. The study population was children admitted with SCHF. Standardized format and tool were used to collect information during assessment. All the collected data were recorded in sheets for analysis. By SPSS version 25.0 for analysis. Bi- variated and multi-variated analysis were also carried out to see and understand the effect of each independent variable on dependent variable. Result: - In this study Eighty-nine percent of the surgery outcome were satisfactory and 11% of the participants had unsatisfactory outcome. Using the Flynn criteria 53%, 36%, 4% and 7% of the supracondylar humeral surgery outcome had an excellent, good, fair and poor respectively. according to the multivariate regression age ≥10 years (AOR=0.22, 95%CI=0.02, 0.78), participant who were from rural area (AOR=0.19, 95%CI=0.02, 0.76) and visits traditional bone setter (AOR=0.11, 95%CI=0.02, 0.53) were a statistically significant factor. Conclusion: open reduction and pinning in majority of children with SCHF have a satisfactory outcome which is the same with the standard in developing countries, children >10 years, children from rural area and those who visited traditional bone setter were factors associated with unsatisfactory outcome. Keywords: Supracondylar, pediatrics, open reduction, pinning and outcome.