Background: For years, the outcome of colorectal cancer (CRC) surgery has been inferior in Denmark compared to its neighbouring countries. Several strategies have been initiated in Denmark to improve CRC prognosis. We studied whether there has been any effect on postoperative mortality based on the information from a national database. Methods: Patients who underwent elective major surgery for CRC in the period 2001-2011 were identified in the national Danish Colorectal Cancer Group database. Thirty-day mortality rates were calculated and factors with impact on mortality were identified using logistic regression analysis. Results: In total, 27,563 patients underwent elective major surgery and their 30-day mortality rate decreased significantly from 7.3 % in 2001-2002 to 2.8 % in 2011 (P < 0.001). Aside from the year of surgery, independent risk factors of mortality were male gender, age ≥61 years, American Society of Anesthesiologists score ≥ II, tumor located in the colon, palliative intent, outcome of surgery "not cured," and open surgical approach. Additionally, 3-month mortality of all 37,022 CRC patients, irrespective of surgical treatment, decreased significantly from 15.8 to 11.3 % during the study period. Conclusion: The 30-day mortality rate after elective major surgery for CRC has decreased significantly in Denmark in the past decade. Laparoscopic surgical approach was associated with a reduction in mortality in colon cancer.