Background: Sleep is vital for recovery during hospital stay. Many sleep-promoting interventions have been investigated in the past. Nurses seem to overestimate their patients sleep and their perspective is needed for these interventions to be successfully implemented. Objectives: To assess the patient's and nurse's agreement on the patient's sleep and factors disturbing sleep. Methods: The instruments used included 1) five Richard-Campbell Sleep Questionnaire (RCSQ) items plus a rating of nighttime noise and 2) the Consensus Sleep Diary (CSD). The mean of the five RCSQ items comprised a total score, which reflects sleep quality. Once a week, unannounced, nurses and patients were asked to fill in questionnaires concerning last night's sleep. Neither nurses nor patients knew the others' ratings. Patient-nurse agreement was evaluated by using median differences and Bland-Altman plots. Reliability was evaluated by using intraclass correlation coefficients. Results: Fifty-five paired patient-nurse assessments have been completed. For all RCSQ subitems, nurses' scores were higher (indicating “better” sleep) than patients’ scores, with a significantly higher rating for sleep depth (median [IQR], 70  vs 50 , P = .012). The Bland-Altman plots for the RSCQ Total Score (r = 0.0593, P = .008) revealed a significant amount of variation (bias). The intra-class correlation coefficient (ICC) indicated poor reliability for all 7 measures (range −0.278 – 0.435). Nurses were relatively overestimating their own role in causing sleep disturbances and underestimating patient-related factors. Conclusions: Nurses tend to overestimate patients’ sleep quality as well as their own role in causing sleep disturbances.