Background: Chronic osteomyelitis (COM) is a bone infection lasting 6weeks or more with radiological evidences. There are few researches done with a focus on Osteomyelitis and even less on chronic osteomyelitis in pediatric patients. In Ethiopia there are few researches done on osteomyelitis in general. So, the aim of this study is to fill this gap. Methods: Hospital based cross-sectional study was done between April 15,2022 and August 15,2022 in children with age of 18 and below visiting Felege Hiwot Comprehensive Specialized Hospital (FHCSH). A total sample size of 168 participants were involved in the study. Random sampling technique was applied to select the study participants. The data was collected from the patients, their charts and x-ray requests. The data was cleaned, stored, checked its completeness and entered to EPI data version 3.1 and then exported to SPSS version 23 for analysis. Descriptive analysis was done and Bivariable and Multivariable logistic regression were used for analysis. Results: The prevalence of Chronic osteomyelitis (COM) was found to be 86.3%. The tibia & femur were the most common involved bones and metaphyseal involvement is very common. The most common radiological findings were sequestrum (56%) and involucrum (53%). Of the total patients with radiological evidences of chronic osteomyelitis 16.6% had complications the most common of which is pathologic fracture (12.4%). Being male [AOR=6.162,95%CI (1.12-34.147)], age group above 10 years [AOR=4.048, 95%CI (1.032-15.886)], rural residency [AOR=4.046, 95%CI (1.236-13.364)] having a discharging sinus [AOR=5.237, 95%CI (1.393-19.693)] clinical complaint duration of more than one year [AOR=5.189,95%CI (1.247-21.588)] and a preceding event of trauma [AOR=10.363,95CI (1.101-97.509)] were associated with getting chronic osteomyelitis. Conclusion: The prevalence of chronic osteomyelitis is high. On this study being male, age group above 10 years, rural residency, having a discharging sinus, clinical complaint duration of more than one year and a preceding event of trauma were factors associated with Chronic osteomyelitis. Therefore, health care providers should have a high index of suspicion of COM in older male children who came from rural areas with a chronic discarding sinus following traumatic events and they should increase the public awareness on bone infections. Keywords: Children, Chronic osteomyelitis, Ethiopia, Magnitude, Radiographic Findings,