This research clearly shows unpleasant odors in hospitals, with the goal of obtaining the basicinformation needed for formulating measures to control such odors. In the study, we conducted asurvey of the odor awareness of nursing staff members at 174 medical institutions, and compared theresults with past research related to odors in nursing homes for the elderly. 88.5% of the nurses sensedodors in hospitals. 81.0% considered it a problem and 67.2% recognized a need for improvement. Themost odorous places included sickrooms, sick wards, sanitary rooms, and lavatories. Among odortypes, excrement odors were most frequently remarked. In addition, there was also body odor,chemical odors from medicines, and the odors of food, tobacco smoke odor, moldy odor, etc. Theodors from the excrement of bedridden patients, patients with urinary incontinence, patients who usediapers, and patients who use portable toilets were presumed to be factors that affected odorenvironment. When the odor level of hospital sickrooms and nursing home bedrooms were compared,increased odor intensity and unpleasantness were observed in sickrooms. It was shown that greatermeasures to control odors are necessary in hospitals than those necessary in nursing homes.