Abstract: The invention concerns methods for effectively sterilizing packaged or unpackaged medical devices such as drug- and/or polymer-coated stents. The method is well-suited to sterilizing medical devices that would be degraded by steam or irradiation sterilization. The present invention involves the placing of a packaged or unpackaged medical device into a pressure, temperature, and humidity controlled environment and exposing the device to a liquid or gaseous sterilizer for a given period of time. An example of a liquid or gaseous sterilizer is ethylene oxide. Given the right temperature, humidity, pressure, sterilizer concentration, and sufficient time, the sterilizer is able to effectively sterilize the device by contacting the exposed surfaces. In the case of packaged medical devices, the sterilizer contacts the device by diffusing through the packaging material.