MAIN PURPOSE: The objective of this study was to determine the relationship between clinician-graded symptoms based on the common toxicity criteria (CTC) and patient-reported quality of life (QoL). We hypothesized that toxicity symptoms that are objective or observable would have a higher correlation with QoL than subjective data. MATERIAL AND METHODS: A retrospective analyses of data from three closed randomized chemotherapy trials was performed. A total of 2,110 patients with ovarian cancer (stage IIB-IV) who had complete toxicity and QoL data at cycles 3 and 6 were included. Toxicities were graded according to the National Cancer Institute Common Toxicity Criteria. Quality of life was assessed every other cycle by using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30). MAIN RESULTS: Correlations between CTC grading and the QLQ-C30 functioning scales were weak (<0.30); correlation coefficients between CTC ratings and the QLQ-C30 symptom scales including nausea, vomiting, constipation, pain, and dyspnea ranged from 0.32 to 0.49 except for constipation (0.55). On a symptom level exact agreement between clinician and patient reporting ranged from 54.2% (pain) to 80.8% (emesis/vomiting). When symptom grading differed, patients reported greater severity for pain, constipation, and dyspnea, whereas clinicians graded emesis/vomiting and nausea as more severe than the grading by patients. CONCLUSION: Patient experience is not routinely captured by CTC toxicity scales. Therefore, clinicians should not entirely rely on the CTC grading but consider patient-reported outcomes as well.