One important device that has evolved within the legal system for dealing with the problem of cognitively incapacitated individuals and the concomitant need for some form of surrogate decision making on their behalf is guardianship. This article outlines the most salient ethical challenges related to guardianship for clinicians who interact professionally with older persons of diminished capacity and their families. Special attention is devoted to the clinician's role in initiating guardianships, questioning the guardian, in the guardianship proceeding, and evaluating the therapeutic impact of guardianship.