Traumatic reticuloperitonitis (TRP) often referred to as hardware disease is a common disease of cattle, which is considered the most frequent cause of anterior abdominal pain in cattle. The incidence of TRP has decreased significantly, but the diagnosis and treatment of TRP are still clinically significant because of its economic impact. An eight-year-old female Mongolian cow weighing 400 kg, was presented to the Korean (College of Veterinary Medicine, Jeju National University)–Mongolian (School of Veterinary Medicine, Mongolian University of Life Science) volunteer team (KMVT) with the primary complaints of depression and anorexia during their outreach activity for veterinary volunteer service in the field of the suburban farm of Mongolia. TRP was diagnosed based on the clinical symptoms, auscultation, and back grip test results. An emergency rumenotomy was performed with the consent of the owner. The patient was anesthetized using distal paravertebral anesthesia and the inverted L block method while a makeshift restraint frame was constructed on-site. The rumenotomy was performed to explore the rumen and reticulum. Foreign bodies were identified and removed. The surgery was performed successfully. The patient’s recovery after the surgery was normal, and the appetite was restored. This paper describes a case of TRP in a Mongolian cow, including the diagnosis, surgical preparation, and surgery successfully performed in the field of suburban farm of Mongolia in detail.