Objective. Patient-reported outcomes (PROs) provide an opportunity to collect important information relating to patient well-being, which is often difficult for physicians to measure (e.g., quality of life, pain, fatigue, and sleep). Here we evaluate the effects of certolizumab pegol (CZP) on PROs during the 24-week, double-blind phase of the RAPID axial spondyloarthritis (SpA) trial, a phase 3 trial of axial SpA patients, including both ankylosing spondylitis (AS) and nonradiographic axial SpA patients. Methods. A total of 325 patients with active axial SpA were randomized 1:1:1 to placebo, CZP 200 mg every 2 weeks, or CZP 400 mg every 4 weeks. The primary end point was the Assessment of SpondyloArthritis International Society criteria for 20% improvement in disease activity response at week 12, and has been reported previously. PROs included total back pain, nocturnal back pain, a daily pain diary, the Sleep Problems Index II (SPI) domain of the Medical Outcomes Study (MOS) Sleep Scale, fatigue, the Ankylosing Spondylitis Quality of Life (ASQOL) measure, and the Short Form 36-item (SF-36) health survey physical component summary (PCS), mental component summary (MCS), and domains. Results. Patients treated with CZP reported significant improvements from week 1 for nocturnal back pain (placebo -0.6, CZP 200 mg every 2 weeks -1.9, and CZP 400 mg every 4 weeks -1.6; P <0.001) and ASQOL (placebo -1.0, CZP 200 mg every 2 weeks -2.3, and CZP 400 mg every 4 weeks -1.9; P <0.05) compared with placebo, while significant improvements in total back pain were seen from day 2. Patients treated with both CZP dosing regimens also had significantly greater improvements in fatigue, MOS-SPI, SF-36 PCS, MCS, and domains compared with placebo. Improvements were similar in both AS and nonradiographic axial SpA patients. Conclusion. Both CZP dosing schedules rapidly improved patient well-being, as measured by PROs, including pain, fatigue, sleep, SF-36, and ASQOL in both AS and nonradiographic axial SpA patients.