Internal noise levels were measured in a 232-point grid that encompassed the main building of a major University Hospital in Valencia, Spain. Most noise equivalent sound levels that were obtained exceeded 55 dBA, and in some instances these sound levels were very high. Hospital workers' subjective responses to noise were evaluated with a self-answered questionnaire. A total of 295 workers volunteered to participate. Their answers revealed that the most important noise sources were located primarily inside the hospital. Noise levels were perceived to be sufficiently high to interfere with their work, and noise levels were also thought to affect patients' comfort and recovery. Most subjects thought it feasible to reduce noise levels in the hospital, and some preventive measures were proposed.