OBJECTIVE Emergency resection and primary anastomosis of unprepared left-colon is a controversial subject. Although this approach has been reported in several series, there is paucity of data on the relative safety of it in viable vs. gangrenous colon especially when the gut is unprepared. METHODS Case records of 57 consecutive patients with acute sigmoid volvulus were reviewed; there were 27 with gangrenous colon (group G) and 30 with viable colon (group V). All of them had undergone emergency resection and primary anastomosis without on-table lavage or caecostomy. RESULTS Group G had a lower mean haemoglobin value (8.4 vs. 9.7 g/dl) and higher incidence of circulatory shock on admission (26% vs. 7%) and required more blood transfusion (85% vs. 53%) than group V. Mean hospital stay (16 vs. 12 days), overall anastomotic leak (15% vs. 27%) and mortality (3.5% vs. 3%) did not differ significantly between the groups. However, the rate of wound infection in Group G was four times greater than that of group V. CONCLUSIONS One-stage restorative resection without on-table lavage or caecostomy appears to be a promising alternative in the emergency management of acute sigmoid volvulus. Comparison of primary anastomosis in gangrenous vs. viable colon did not reveal any significant difference in hospital stay, rate of anastomotic leak or mortality. However, the risk of wound infection was more in patients with gangrenous sigmoid volvulus.