Abstract
It has recently been argued by Faunce and McSherry1 that appellate courts have an important educative and regulatory role in respect of professionals, a role which they maintain the courts have not been discharging well enough. Two important cases in Victoria2 and South Australia3, however, have recently articulated a series of principles for the giving of opinion evidence on matters related to mental health expertise. Scrutiny by prosecutors and experts of the defects highlighted by the courts in the evidence elicited at trial in the two cases and of the principles identified by the courts has the potential to make significant improvements in relation to the giving of expert evience by psychiatrists and psychologists.