Objective: To evaluate the feasibility of a computerized mattress system based on a novel concept in sore prevention: continuous monitoring and adjustment of the interface pressure in small segments of contact between the skin and the supporting surface. Design: A preliminary observational study. Setting: The Spinal Department, Loewenstein Rehabilitation Hospital, Raanana, Israel. Subjects: Twelve patients with spinal cord lesions. Interventions: Patients were examined for signs of impending sores after lying on the mattress for up to 4 successive hours. The pressure within each of the mattress's air cells was continuously measured and adjusted. Results: No evidence of redness or excessive perspiration was found in any of the areas considered to be high risk for bed sores. Maximal interface pressure was 22-30 mmHg in most of the examinations. Most of the patients felt comfortable on the mattress and the staff adapted easily to its operation. Conclusions: The system is apparently safe, and at least as efficient as other existing means for preventing sores. In addition, it may allow for increased intervals between bed positionings. We conclude that this approach of pressure control has the potential to improve bed sore prevention in a rehabilitation hospital setting.