A method for cleaning and sterilizing a medical device comprises the steps of: a) placing the device into a container, b) cleaning the device with a cleaning solution, c) rinsing the device with rinse solution, d) treating the device with a liquid sterilant, e) vaporizing the liquid sterilant in the container thereby simultaneously sterilizing and drying the device, and providing a sterile, dry product without further rinsing. The method further comprises retaining a predetermined amount of the liquid sterilant in the container prior to step e). Step e) can be conducted under a diffusion restricted environment, or by reducing pressure to a first predetermined pressure followed by further reducing the first pressure to a predetermined second pressure, or at controlled pump down rate.