In colorectal cancer, the relation between duration of symptoms and stage at presentation and prognosis is not yet settled. All 1263 patients treated for colorectal cancer at Levanger Hospital, 1980-2004, and 2892 patients treated in Norway during 2004 were included. The association between symptom duration as an explanatory variable and tumour stage as a dependent variable was analysed using a proportional odds logistic regression model. Known duration of symptoms was divided into four categories: <1 week, 1-8 weeks, 2-6 months and >6 months. There was an inverse relationship between symptom duration and colon cancer TNM-stage, OR=0.73 (95% CI 0.63-0.84), p<0.001 (Levanger Hospital) and 0.84 (0.75-0.95), p=0.004 (Norway 2004), where the OR is per category of symptom duration. Duration of symptoms were also inversely associated with T-stage, N-stage and M-stage in colon cancer. These relationships were not found for rectal cancer. In colon cancer the relative five-year survival for the four intervals of symptom duration was 44%, 39%, 54% and 66%, p<0.001, in Levanger, 1980-2004, and four-year survival was 46%, 62%, 75% and 74%, p<0.001, in Norway 2004, respectively. For rectal cancer survival was not dependent on symptom duration. In a multivariate analysis of relative survival of patients with colon cancer, duration of symptoms was associated with survival independent of tumour differentiation and TNM-stage. Increasing duration of symptoms was positively associated with less advanced disease and better survival in colon cancer, but not in rectal cancer.