A medical waste disposal apparatus for receiving and retaining waste articles, such as catheter fittings, and the like, for controlled and facilitated handling and disposal of such waste articles, during and following the performance of treatment procedures on a patient by a practitioner. The waste disposal apparatus includes a first retaining member, mounted on a base panel, for receiving and retaining a waste article placed there by a practitioner during a treatment procedure, and further includes at least one side panel, for covering the waste article, after placement of the waste article on the first retaining member. Alternative configurations of retaining members are provided.