BACKGROUND: Colorectal cancer affects a wide range of working-age people. Little is known about the consequent work limitations. OBJECTIVE: The aim of this study was to understand the extent and changing nature of work-related limitations of middle-aged (45-64 years) people over the first 12 months of colorectal cancer. METHODS: Surveys were administered to participants recruited via the Queensland Cancer Registry, at 6 and 12 months after diagnosis. Among those who returned to work, the Work Limitations Questionnaire measured 4 job performance domains (time management, physical, mental-interpersonal, and output demands) and an overall productivity score. Open-ended questions supplemented the Work Limitations Questionnaire, and responses were thematically analyzed. RESULTS: Of 239 participants, 8% did not continue in the study, and 20% left employment by 12 months, leaving 171 participants eligible for this analysis. Open-ended responses for why participants stopped work included bowel problems and stoma, loss of strength, and medication adverse effects. At 12 months, 22% to 39% of participants reported work limitations, but there was no overall significant change in work limitations between 6 and 12 months. Qualitative data highlighted the key work-related issues were changes in work functioning, attitudes of employers and colleagues, financial pressures, and emotional responses. CONCLUSIONS: While a significant proportion left work because of treatment-related problems, and the majority of participants did not experience workplace limitations, some reported considerable work-related challenges. IMPLICATIONS FOR PRACTICE: Discussions with health professionals about the possible impact of treatment adverse effects on employment, good communication with employers, and workplace flexibility may facilitate return to work for this population.