Systems and methods for decontaminating a surgical drain and its reservoir are provided. An apparatus is provided in the form of a container having an interior chamber and an expansible opening to the interior chamber for insertion of a surgical drain therethrough. Ultraviolet light emitters are disposed within the interior chamber to emit beams of ultraviolet radiation at the surgical drain and/or its reservoir, thereby killing or neutralizing bacteria and fungus on the drain. Walls forming the expansible opening are collapsible to abut a portion of the inserted drain when inserted into the apparatus, and a fluid tight seal is formed between the drain and the apparatus.