BACKGROUND Hospitals should provide a quiet environment to promote patient healing and well-being. However, published data indicates that World Health Organization's guidelines are frequently not met. The aim of the present study was to quantify night-time noise levels in an internal medicine ward and evaluate sleep quality, as well as the use of sedative drugs. METHODS Prospective observational study in an acute internal medicine ward. Between April 2021 and January 2022, on random days, noise was recorded using a smartphone app (Apple® iOS, Decibel X). Night-time noise was recorded from 10 p.m. to 8 a.m. During the same period, hospitalized patients were invited to respond to a questionnaire regarding their sleep quality. RESULTS A total of 59 nights were recorded. The average noise level recorded was 55 dB with a minimum of 30 dB and a maximum of 97 dB. Fifty-four patients were included. An intermediate score for night-time sleep quality (35.45 out of 60) and noise perception (5.26 out of 10) was reported. The main reasons for poor sleep were related to the presence of other patients (new admission, acute decompensation, delirium, and snoring), followed by equipment, staff noise and surrounding light. Nineteen patients (35%) were previous users of sedatives, and during hospitalization 41 patients (76%) were prescribed sedatives. CONCLUSIONS The noise levels detected in the internal medicine ward were higher than the levels recommended by the World Health Organization. Most patients were prescribed sedatives during hospitalization.