According to an aspect of the invention, an indwelling catheter is provided which comprises a catheter shaft. The catheter either comprises a light source or is adapted to receive light from a light source, and is configured such that light is transmitted from the light source into the catheter shaft. Moreover, the catheter shaft is formed of a polymeric material that transmits a quantity of light from the light source that is effective to inactivate microorganisms on a surface of the catheter shaft upon activation of the light source. For example, the light may inactivate the microorganisms directly or in conjunction with a photosensitizer. According to another aspect of the invention, a sterilization method is provided, which comprises activating the light source while the catheter is inserted in a subject.