The purpose of this study was to test and describe in detail a newly developed comprehensive system for washing, pre-disinfecting and sterilizing of dental and surgical instruments. The system consists of a combined washing and steam-operated pre-disinfection apparatus and newly developed trays, in which assorted instruments can be washed and disinfected without handling individual instruments. The system was subjected to a large number of tests. The cleaning efficiency of blood-soiled instruments was found to be excellent. The disinfection of dental instruments contaminated with bacteria, yeast and non-enveloped virus showed decimal reduction factors that were equivalent to sterilization. The trays had optimal sealing qualities. Their steam permeability was perfect even after prolonged use in N-, S- and B-type autoclaves. However, long-term tests in a clinic revealed shortcomings with regard to insufficient drying of instruments in the wash/disinfection apparatus. Furthermore, the mechanical stability of the polysulfonate tray covers needs to be improved. Occasionally, after extended use, the fit of the filters in metal trays became inadequate, in particular when trays were sterilized for 18 min at 134°C for a prolonged period of time. In spite of the above-mentioned shortcomings, the system shows great labor and cost-saving potential, allowing a new approach to instrument recirculation and workflow in the dental office. Keywords: dental office hygiene, pre-disinfection of instruments, new dental trays