Introduction: Most colonic injuries are due to penetrating abdominal trauma. Colon injury rarely occurs after blunt abdominal trauma. Colonic trauma is usually associated with other intra-abdominal and extra-abdominal injuries. The low incidence of colon injury due to blunt abdominal trauma and the lack of a definitive diagnostic method for the same can lead to delays in diagnosis and treatment, subsequently resulting in high morbidity and mortality. Case presentation: a 25-years-old man who present after seven days of blunt abdominal trauma with clinical evidence of peritonitis, on laparotomy isolated sigmoid colon perforation was found which was managed with end colostomy. Conclusion: Isolated colon injury after blunt abdominal trauma is rare and difficult to diagnose. Delay in diagnosis increases the morbidity and mortality rates. Therefore it is important for the trauma surgeon to keep high index of suspicion colonic perforation, to facilitate its timely diagnosis and management.