A procedure-oriented isolation system, Category 1, 2, 3, and 4, was introduced at a 547-bed, acute and rehabilitative medical center. The system consisted of four categories of isolation which followed a numerical sequence that represented the necessary attire needed to complete the procedure. After 1 year of use, personnel compared the procedure-oriented system with the previously-used system (Strict, Respiratory, Wound and Skin, Enteric, and Limited Barrier). Personnel found the procedure-oriented system easier to understand (84%) and follow (83%). Seventy-six percent felt their isolation techniques had improved with the new system. A reduction in the cross-infection rate with methicillin-resistant Staphylococcus aureus did coincide with the use of the new isolation system, however, no causal relationship was established. The Category 1, 2, 3, and 4 isolation system was well received by personnel and was found to be an effective alternative to the previous, more complicated system used in this setting. Further evaluation of this system in other settings would seem warranted.