Background: When a policy encouraging day of surgery admission (DOSA) was introduced in public hospitals in New South Wales, Australia, there were concerns that patient outcomes would be compromised. The aim of the present study was to compare patients having an elective resection for colorectal cancer (CRC) on a DOSA and a non-DOSA basis in respect of postoperative complications, operative mortality and 2-year survival. Methods: A comprehensive prospective computerized database is maintained for all patients undergoing a resection for CRC at Concord Hospital, Sydney, Australia. The present study is based on patients who had an elective resection during the transition to DOSA between January 2000 and December 2003. Background characteristics, comorbidity, perioperative factors, tumour pathology, postoperative morbidity and mortality, and overall survival were compared between 274 DOSA and 103 non-DOSA patients. Results: Of the 24 postoperative complications considered there was a significant difference in only four: DOSA patients were less likely than non-DOSA patients to have a respiratory complication (16.1% vs 29.1%, P = 0.004), a prolonged organic confusional state (5.5% vs 23.3%, P < 0.001), acute drug withdrawal (0.4% vs 3.9%, P = 0.021) or multisystem failure (0.4% vs 3.9%, P = 0.021). There was no difference in operative mortality or 2-year survival. Conclusion: The present study shows that DOSA did not adversely affect a wide range of outcomes for patients having a resection for CRC. In fact the results suggest that DOSA may protect against respiratory complications and prolonged postoperative confusion.