The supervision of psychotherapy in institutions can take a variety of forms. In all cases, the dynamics of the triad that consists of the patient, the therapist and the supervisor is interwoven with the dynamics of the institution itself, of the staff team and of the relation between the supervisor and the service. As a consequence, the supervision is influenced by many more uncontrolled variables than usual. The supervisor has to take into consideration, and to balance, the real facts about the setting and the needs of trainees, as well as the dynamics of the team and the organisation, which produce massive projections and multiple transference, which inevitably triggers feelings of countertransference. The supervision process is affected not only by the dynamics of the supervisor -supervisee-patient triad, but by the dynamics of the institution which provides the supervisory setting.