Purpose: To assess the impact of delay from diagnosis to curative surgery on survival in patients with non-metastatic colon cancer. Methods: National Cancer database (NCDB) analysis (2004-2013) including all consecutive patients diagnosed with stage I-III colon cancer and treated with primary elective curative surgery. Short and long delays were defined as lower and upper quartiles of time from diagnosis to treatment, respectively. Age-, sex-, race-, tumor stage and location-, adjuvant treatment-, comorbidity- and socioeconomic factors-adjusted overall survival (OS) was compared between the two groups (short vs. long delay). A multivariable Cox regression model was used to identify the independent impact of each factor on OS. Results: Time to treatment was <16 days in the short delay group (31,171 patients) and >= 37 days in the long delay group (29,617 patients). OS was 75.4 vs. 71.9% at 5 years and 56.6 vs. 49.7% at 10 years in short and long delay groups, respectively (both p < 0.0001). Besides demographic (comorbidities, advanced age) and pathological factors (transverse and right-vs. left-sided location, advanced tumor stage, poor differentiation, positive microscopic margins), treatment delay had a significant impact on OS (HR 1.06, 95% CI 1.05-1.07 per 14 day-delay) upon multivariable analysis. The adjusted hazard ratio for death increased continuously with delay times of longer than 30 days, to become significant after a delay of 40 days. Conclusion: This analysis using a national cancer database revealed a significant impact on OS when surgeries for resectable colon cancer were delayed beyond 40 days from time of diagnosis. (C) 2019 Elsevier Ltd, BASO similar to The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.