Report results of patient-reported health-related quality of life (HRQoL) and symptoms from phase III KEYNOTE-006 study of pembrolizumab versus ipilimumab in patients with ipilimumab-naive advanced melanoma.Patients received pembrolizumab 10 mg/kg every 2 (Q2W) or every 3 weeks (Q3W) for up to 2 years, or four cycles of ipilimumab 3 mg/kg Q3W. The European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30 (EORTC QLQ-C30) was administered at baseline and throughout the study. Patient-reported outcome (PRO) analyses were pre-specified exploratory endpoints; the primary PRO assessment was the score change from baseline to week 12 in EORTC QLQ-C30 global health status (GHS)/HRQoL score between the arms using constrained longitudinal data analysis.The PRO analysis population included 776 patients: pembrolizumab Q2W (n = 270); pembrolizumab Q3W (n = 266); ipilimumab (n = 240). Baseline GHS was similar across arms. QLQ-C30 compliance rates at week 12 were 87% (n = 214), 97% (n = 226), and 96% (n = 178), for the pembrolizumab Q2W, pembrolizumab Q3W, and ipilimumab arms, respectively. From baseline to week 12, GHS/HRQoL scores were better maintained with pembrolizumab than with ipilimumab (decrease of -1.9 and -2.5 for pembrolizumab versus -10.0 for ipilimumab; p < 0.001 for each pembrolizumab arm versus ipilimumab). Fewer patients treated with pembrolizumab experienced deterioration in GHS at week 12 (31% for pembrolizumab Q2W; 29% for Q3W and 44% for ipilimumab), with similar trends observed for individual functioning and symptoms scales.HRQoL was better maintained with pembrolizumab than with ipilimumab in patients with ipilimumab-naive advanced melanoma. CLINICALTRIALS.NCT01866319.