The General Medical Council's document 'Tomorrow's Doctors' (1993, GMC, London) recommended major changes in the undergraduate curricula of UK medical schools. In Nottingham, the fourth-year psychiatric attachment became shorter in duration, and interactive, problem-oriented, workshop-based learning replaced lectures. We compared the efficacy of this new teaching style in changing medical students' attitudes towards psychiatry and mental illness with that of old-style, didactic, lecture-based teaching. On the first and last days of their psychiatric attachment, 110 fourth-year medical students (45 old curriculum; 65 new curriculum) completed two self-administered attitudinal measures: the Attitude to Psychiatry Questionnaire (ATP-30) and the Attitude to Mental Illness Questionnaire (AMI). We found that students had favourable attitudes towards psychiatry and mental illness before the attachment. These attitudes became more positive after the attachment in students from both curricula, with no significant difference between the groups and no gender difference. Students found patient contact rewarding, become more accepting of community care, and had greater appreciation of the therapeutic potential of psychiatric interventions. The interactive, student-centred, problem-oriented teaching of the shortened new curriculum appeared as effective in changing medical students' attitudes as a longer attachment with traditional teaching.