There has been increasing concern recently over an apparent lack of knowledge of mental health law among psychiatrists and other medical practitioners involved in its use. This has been particularly highlighted by the introduction of new and complex legislation intended to facilitate care in the community. As a result of findings from previous studies of other groups of medical practitioners in Scotland, a national survey of consultant psychiatrists working there was undertaken to determine their level of understanding of the statutory provision for the care of the mentally disordered. A purpose-designed instrument was used at interview with 72 consultants chosen at random from all psychiatric specialties. Their knowledge of even the most basic definitions and fundamental areas was limited, with only just over half being able to give the correct title of one relevant piece of legislation and only one in 10 being able to define mental disorder in terms of the Act. Otherwise knowledge was generally patchy. Greater emphasis should be placed upon training in mental health law for consultant psychiatrists in general, as the findings are unlikely to reflect purely localized patterns. Attitudes to the use of compulsory measures also need to be addressed.