This study was designed to test the efficacy of a washer-disinfector in eliminating selected healthcare-associated pathogens from surgical instruments. Our results showed that a washer-disinfector was extremely effective in eliminating microorganisms (>7-log(10) reduction), including vegetative and spore-forming bacteria, from experimentally contaminated instruments. The washer-disinfector remained effective in eliminating microorganisms in the absence of enzymatic cleaners and detergents.