Sleep dysfunction in patients with rotator cuff tears has been previously evaluated only using subjective measures. Objective parameters of sleep quality amongst rotator cuff tear patients are scarce in the literature. The aim of this study is to compare objective sleep data to historical controls and to subjective patient-reported sleep quality in patients with rotator cuff tears.We hypothesized that patients with rotator cuff tears would demonstrate objectively poor sleep quality based on actigraphy when compared to a historical control group. Secondarily, we hypothesize that objective sleep quality measures will correlate poorly with traditionally used questionnaires and other subjective assessments.Twenty patients with full-thickness rotator cuff tears wore a highly validated activity monitor for 2 consecutive weeks for objective assessment and completed a sleep diary during the same period. Patients completed multiple questionnaires pertaining to their shoulder function and subjective assessment of sleep quality. Objective sleep assessments were compared to patients' sleep diary data and to subjective sleep data from a historical cohort of 969 healthy adults aged 57-97 years.Mean total sleep time, sleep onset latency, wake after sleep onset (WASO), and sleep efficiency were all significantly worse in the study cohort compared to the historical cohort (p=0.0338, p=0.0040, p<0.0001, and p=0.0474, respectively). Pittsburgh Sleep Quality Index (PSQI) scores did not correlate with sleep efficiency (r=0.3143, p=0.2040) or WASO (r=-0.3068, p=0.2153). Visual analog scale scores correlated with PSQI scores (r=0.5260, p=0.0249) and Epworth Sleepiness Scale scores (r=0.4863, p=0.0407). Patients tended to overreport their time spent asleep via a sleep diary compared to objective time asleep (p=0.0050).This study of objective sleep measures demonstrated poor sleep quality in patients with rotator cuff tears with shorter sleep duration, frequent awakenings, and decreased efficiency. Subjective assessments of sleep did not correlate with objective findings.Level II, prospective cohort study.