OBJECTIVES: In clinical trials, chemotherapy-related adverse events (AEs) are classified according to the Common Toxicity Criteria (CTC). This standardised method of reporting provides clinicians with an overview of the level of medical intervention required to treat AEs, but does not necessarily assess the impact on a patient's health-related quality of life (HRQL). We attempt to translate CTC (version 2.0) ratings into a scale that reflects the severity of various events on a patient's HRQL. METHODS: In this study, scores of impact on patient HRQL were assigned to AEs experienced by advanced non-small cell lung cancer (NSCLC) patients receiving second-line chemotherapy. This was achieved through a pilot survey of a convenience sample of twelve physicians. A mapping instrument was developed to allocate values of HRQL impact to fifty chemotherapy-related AEs. The HRQL impact was measured on a five-point scale for direct comparison with the CTC. RESULTS: This analysis revealed that approximately half (23 of 50) of the AEs had HRQL impact values that were different to their CTC grades. For the majority (17 of 23), the HRQL impact value was lower than the CTC grade. The results of the HRQL impact survey confirmed that the CTC classification does not always reflect the impact on patient HRQL and that in general, low to moderate grade leukopenic and thrombocytopenic haematological events have lower impact on patient HRQL than non-haematological events. Vomiting, pain, sensory neuropathy, rigors, chills and fever had a higher impact on HRQL than the CTC would suggest. CONCLUSIONS: We have proposed a method for estimation of the HRQL impact of AEs on chemotherapy patients that has face validity. This research provides a basis to quantify the HRQL impact of chemotherapy-related AEs. This could then be used to assess the value of various chemotherapy agents in cost-utility analyses.