The aim of this study was to compare the incidence of abdominal and incisional hernias in patients with abdominal aortic aneurysm (AAA) versus patients with aortoiliac occlusive disease (AOD). The study included retrospectively 121 patients, who underwent elective aortic surgery due to AAA (n = 63) or AOD (n = 58) in the period between January 1998 and January 2000. The patients were examined for the presence of abdominal hernias upon admission, as well as for the development of incisional hernias on follow-up. The incidence of inguinal hernias was significantly higher in the group AAA (21/6-33.3%) compared to the group with AOD (6/58-10.3%) (p < 0.01). The incidence of other abdominal wall hernias (umbilical, epigastric or miscellaneous hernias) was also significant higher in AAA group. Furthermore, the incidence of inguinal hernias was significantly higher in the subgroup of patients with an aneurysm diameter more than 6 cm (41.5% vs 18.2%, p < 0.05). The mean follow-up of the patients was 1.7 +/- 0.3 years. 7 cases of incisional hernia were noted in the AAA group (11.1%) and only 2 cases in the AOD group (3.4%) (p < 0.05). The size of the aneurysm had no influence on the incidence of incisional hernias in the AAA group. We conclude that there seems to be an increased incidence of abdominal wall hernias as well as postoperative incisional hernias in patients undergoing aortic surgery for aneurysm disease compared with aortoiliac occlusive disease.