The psychiatric ratings, using the In-Patient Multi-dimensional Psychiatric Scale, of (1) a group of over 200 psychiatrists from the British Isles, (2) third year psychology students, (3) trainee sister tutors, (4) general practitioners attending a postgraduate course in psychiatry, and (5) a group of new registrars at the Maudsley Hospital, were compared. The first hypothesis, that, whereas the non-psychiatrists would rate similar levels of symptoms, the psychiatrists would tend to rate lower than other professional groups, was upheld. The second, that the pattern or profile of symptoms as shown by the IMPS syndromes would differ little between the groups, was also upheld. The third hypothesis, that because of their special training in the recognition of symptoms, psychiatrists would tend to show greater intra-group agreement on the levels of symptoms than the other groups, was not upheld. Some possible reasons for the findings are discussed. The importance for a screening schedule, designed to be used by non-psychiatrists for the detection of psychiatric illness, of the finding that non-psychiatrists rate higher levels of symptoms than psychiatrists, is also discussed.