Accurate assessment of health-related quality of life (HRQoL) in patients with advanced colorectal cancer is essential to improve our understanding of how cancer and chemotherapy influence patients' life and to adapt treatment strategies. Specific questionnaires have descriptive and predictive value and can be used to evaluate new therapies. Results from HRQoL assessments in randomised trials help patients and physicians to choose between treatment options. More than half of the patients treated with palliative chemotherapy have an improvement or at least a preservation of their HRQoL. However, several trials have found small differences in HRQoL between treatment groups. This may be due to the insufficient sensitivity of tools, low numbers of patients or missing data. An international consensus on the methods of measurement of HRQoL in oncology is warranted to enhance compliance, to better interpret results and to optimise the publication of precise HRQoL data.