The detection of emotional disturbance by general practitioners in the consultation is known to be low. This study measured the detection rates of emotional disturbance among 10 established principals in general practice, as compared with the general health questionnaire, before and after 10 months of training. The training comprised a fortnightly seminar based around video recordings of ordinary consultations. The results showed that nine of the 10 doctors improved their ability to identify cases while one over-diagnosed cases following the training. The general health questionnaire detected emotional disturbance in 51.5% of the patients studied. During the seminars it became apparent that factors both within the doctor and the patient prevented detection of emotional disturbance and these are described. It is concluded that diagnostic accuracy depends on the interaction between doctor and patient, and that this has implications for the organization of general practice both in terms of longer consultation times and of adequate support for the doctor.