Introduction: The UK Medical Research Council CLASICC trial assessed the safety and efficacy of laparoscopically assisted surgery in comparison with open surgery for colorectal cancer. The results of the 5‐year follow‐up analysis are presented. Methods: Five‐year outcomes were analysed and included overall and disease‐free survival, and local, distant and wound/port‐site recurrences. Two exploratory analyses were performed to evaluate the effect of age (70 years or less, or more than 70 years) on overall survival between the two groups, and the effect of the learning curve. Results: No differences were found between laparoscopically assisted and open surgery in terms of overall survival, disease‐free survival, and local and distant recurrence. Wound/port‐site recurrence rates in the laparoscopic arm remained stable at 2·4 per cent. Conversion to open operation was associated with significantly worse overall but not disease‐free survival, which was most marked in the early follow‐up period. The effect of surgery did not differ between the age groups, and surgical experience did not impact on the 5‐year results. Conclusion: The 5‐year analyses confirm the oncological safety of laparoscopic surgery for both colonic and rectal cancer. The use of laparoscopic surgery to maximize short‐term outcomes does not compromise the long‐term oncological results. Registration number: ISRCTN74883561 (http://www.controlled‐trials.com). Copyright © 2010 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. Confirms safety of laparoscopy