Background: The increase in prevalence of colorectal cancer among young patients coupled with an older retirement age in developed countries means that more patients are being diagnosed with colorectal cancer while still at work. The aim of this study was to develop prediction models for return to work by 1 and 2 years after the start of sick leave. Methods: This was a retrospective registry-based cohort study of data from a nationwide occupational health service in the Netherlands. Only employed patients with colonic or rectal cancer treated with curative intent were included. Two predictor variable models were developed using multivariable logistic regression with backward selection. Calibration, discrimination and explained variance were used to assess model performance, and internal validation by bootstrapping was performed. Results: Median time to return to work for 317 included patients was 423 (95 per cent c.i. 379 to 467) days. Two-thirds of patients had returned to work by 2 years after the start of the sick leave. Presence of metastases, adjuvant treatment, stoma, emotional distress and postoperative complications were predictors of not returning to work in the 1-year model. In the 2-year model, presence of metastases, emotional distress, postoperative complications, company size and the trajectory of the return-to-work process were predictors. Conclusion: Almost 70 per cent of patients with colorectal cancer in this population returned to work within 2 years after the start of sick leave. The models can be used to guide patients early in colorectal cancer treatment about the likelihood of returning to work, and to identify and modify barriers that could facilitate this.