Psychiatric advance directives (PADs) are intended to support patients' treatment decisions during a crisis. However, PAD statutes give clinicians broad discretion over whether to carry out patients' advance instructions. This study uses data from a survey of psychiatrists (N=164) to examine reasons for overriding PADs. In response to a hypothetical vignette, 47% of psychiatrists indicated that they would override a valid, competently-executed PAD that refused hospitalization and medication. PAD override was more likely among psychiatrists who worked in hospital emergency departments; those who were concerned about patients' violence risk and lack of insight; and those who were legally defensive. PAD override was less likely among participants who believed that involuntary treatment is largely unnecessary in a high-quality mental health system.