PURPOSE: The aim of this study was to investigate the clinical and radiological incidence of parastomal hernia. METHODS: We reviewed, retrospectively, 83 patients with end colostomy operated on from January 2003 to June 2009 at Ajou University hospital. Age, sex, surgical procedure type, body mass index (weight/length2), stoma size, and respiratory co-morbidity were documented. We compared the incidence of radiological and clinical parastomal hernia. RESULTS: There were 47 males (56.6%) and 36 females (43.4%). During an overall median follow-up of 30 months (range, 6 to 45 months), 24 patients (28.9%) developed a radiological parastomal hernia postoperatively and 20 patients (24.1%) presented clinical symptoms. Using computed tomography (CT) classification, the groups were as follows: type 0 (40, 48.2%), type Ia (19, 22.9%), type Ib (8, 9.6%), type II (4, 4.8%) and type III (12, 14.5%), with 63 asymptomatic patients and 20 symptomatic patients. The aperture size was significantly different between symptomatic and asymptomatic patients (76.45 mm vs. 49.41 mm; P = 0.000). There was a significant correlation between aperture size and the radiological type (P = 0.003). CONCLUSION: This study showed the incidence of radiological parastomal hernia is acceptable compared to previous studies. CT classification may be useful to evaluate parastomal hernia.