Purpose : To find numbers of pressure-reducing mattresses and problems associated with it in large hospitals. Method : In July 2004, we mailed questionnaires to main personnel who deal with patients with pressure ulcers of 854 hospitals that has more than 400 beds based on Japanese hospitals yearbook. Results : We collected questionnaires from 384 hospitals (45%). We analyzed data from 212 hospitals, that had accurately knew the numbers of pressure-reducing mattresses in the institution. The average numbers of such mattresses per 100 beds were 20.7 (ranged 1.0 to 110). It was found the correlation coefficient between the number of those mattresses and "standard of care" was r=0.301. We found those mattresses were managed by nursing units, by centrally-located departments, and by both of them. Names of the mattresses include recent manufactured goods. Hospitals with "Care Standard of Pressure Ulcers" had more mattresses than hospitals without it (p=0.073). The average amount of money spent on mattresses in the year 2003 was 1840000yen, and in the year of 2004, 37% hospitals budgeted to purchase such mattresses. 19% felt they had enough mattresses. Discussion : It was found hospitals with more beds, better bed turnaround rate, and with more nurses found to have more pressure-reducing mattresses and equipped better to deal with patients with pressure ulcers. By looking at the brands of mattresses, it is apparent that many of them were high functional and recently purchased. It is thought that personnel who deal with patients with pressure ulcers think they don't have enough mattresses but because of restrained budget they don't purchase them. In the future, not only those departments that deal with patients with pressure ulcers directly but also the entire institution is expected to deal with pressure ulcers by budgeting and managing such mattresses.