Purpose: Chemotherapy-induced nausea and vomiting (CINV) are major adverse effects of cancer chemotherapy. We compared the impact of acute (during the first 24 hours postchemotherapy) and delayed (days 2 through 5 postchemotherapy) CINV on patients' quality of life (QoL) after highly or moderately emetogenic chemotherapy (HEC and MEC, respectively). Patients and Methods: This prospective, multicenter, multinational study was conducted in 14 medical practices on cancer patients undergoing either HEC or MEC treatment. Patients recorded episodes of nausea and vomiting in a diary. Patients completed the Functional Living Index-Emesis (FLIE) questionnaire at baseline and on day 6. Results: A total of 298 patients were assessable (67 HEC patients, 231 MEC patients). Emesis was reported by 36.4% of patients (13.2% acute, 32.5% delayed) and nausea by 59.7% (36.2% acute, 54.3% delayed). HEC patients reported significantly lower mean FLIE total score than MEC patients (95.5 v 107.8 respectively; P = .0049). Among all patients, the nausea score was significantly lower than the vomiting score (50.0 and 55.3, respectively; P = .0097). Of the 173 patients who experienced neither vomiting nor nausea during the first 24 hours postchemotherapy, 22.9% reported an impact of CINV on daily life caused by delayed CINV. Conclusion: CINV continues to adversely affect patients' QoL despite antiemetic therapy even after treatment with only moderately emetogenic chemotherapy regimens, and even in the subgroup of patients who do not experience nausea and vomiting during the first 24 hours. On the basis of the FLIE results in this study, nausea had a stronger negative impact on patients' daily lives than vomiting.