['High-quality chest compressions (CCs) are an important component of successful resuscitation. Suboptimal in-hospital CC are commonly reported. Skill degradation and fatigue have been implicated. We assessed the effect of a handheld feedback device on the measured and perceived quality of CC and rescuer physiologic response.', 'This is a nonblinded randomized controlled study of nurses at an academic medical center. Participants performed CC on a mannequin either with or without a feedback device. Compression rate (CR) and compression depth (CD), heart rate, and oxygen saturation were documented. Perceived quality of CC, fatigue, and ease of use of the device were obtained.', 'Twelve nurses were in the feedback group (FG) and 13 were controls. Mean CD was significantly higher in the FG (1.99 ± 0.37 in vs 1.52 ± 0.36 in; P = .005) and mean CR significantly lower in the FG (127 ± 13.8 per min vs 101 ± 9.7 per min; P ≤ .0001). Using a CD of more than 1.5 in and a CR of 90 to 100 as a composite measure of high-quality CC, the FG performed significantly better (81.4% ± 22.0% vs 10.4% ± 21.9%; P < .0001). Perceived CD, CR, and fatigue did not differ between groups; however, participants overestimated depth and underestimated rate. The FG rated the design as user-friendly (85% + 26%) helpful in maintaining correct CR (83% + 26%).'] Does cardiopulmonary resuscitation feedback improve the quality of chest compression provided by hospital health care professionals?