Male patients of two hospitals in Belo Horizonte completed a questionnaire during an interview on the day of discharge in order to evaluate sleeping conditions related to noise during the previous night and were retested 24 h later. Patients had a worse perception of sleep at the noisier hospital, the University Hospital of the Federal University of Minas Gerais (N = 13), whose internal mean nocturnal noise level was Leq = 53.7 db(A), than at the quieter hospital, Baleia (N = 22), whose internal mean nocturnal noise level was Leq = 45.5 db(A). Noise was the only sleep-disturbing factor which was statistically significant.