Abstract Background The Dutch Cancer Society proposed that the interval between diagnosis and start of treatment should be less than 15 working days. The purpose of this study was to determine whether the interval from diagnosis to treatment for patients with colorectal cancer (CRC) shortened between 2005 and 2008 in hospitals in southern Netherlands. Methods Patients with CRC diagnosed in six hospitals in southern Netherlands during January to December in 2005 ( n = 445) and January to July in 2008 ( n = 353) were included. The time between diagnosis and start of treatment was assessed, and the proportion of patients treated within the recommended time (<15 working days) was calculated. Results The time to treatment for colon cancer patients was 13 working days in 2005 and 17 working days in 2008. For rectal cancer patients, the median time to preoperative radiotherapy was 28 working days in 2005 and 30 working days in 2008, and the median time to surgical treatment for rectal cancer patients was 26 working days in 2005 and 18 working days in 2008. Time to treatment did not shorten between 2005 and 2008 for colon and rectal cancer patients, except for rectal cancer patients who underwent surgery as initial treatment in patients aged >70 years and those with stage I disease. Substantial variation was seen among hospitals. Conclusions Time to treatment for patients with CRC in southern Netherlands did not shorten between 2005 and 2008. The time to treatment should be reduced to meet the advice of the Dutch Cancer Society.