Introduction & Objective: Infection of the post orthopedic surgery is one of the most prevalent complications after surgery that causes the increase of bed occupancy, hospitalization time and costs for patient. Up to now, little study has been done on the prevalence of orthopedic surgical site infection. This study was done with purpose of “Assessment of the prevalence of post-operation orthopedic wound infection in the orthopedic surgical ward of Motahari hospital”. Materials & Methods: This is a descriptive- analytic study. Sampling was done with census method in 420 patients of orthopedic surgery in 2009-2010. We prepared a checklist with the use of brain storm, fishbone diagram, review article and group discussion methods in three parts which involved patient, accident and hospital and the computed its superficial reliability and durability (r = 0.086). Data collected through interview and observation. SPSS 12 was used for data analysis. Results: Patients mean age was 36.47±23.58 years, anesthesia time was 0.17±0.57 hr and days of hospitalize was 7.02±4.2. Chi-square test showed significant correlation between surgical site infection and fracture kind, smoking, operation time, operation kind, and days of hospitalization. Prevalence of orthopedic infection was 8.8%. Conclusions: Preparation of a standard hospital performance protocol should be done with the purpose of decrease orthopedic infection prevalence via increasing the attention to leg and open fractures specially in smoking people.