This study reports the findings of a sociological inquiry into general practioners' perception of mental health. The research on which it is based was done in the province of Groningen in 1961. First comes an orientation in the re'levant literature. The concept of mental health care is specified as the psychiatric care, to be provided by medicalinstitutions. Mental health care is seen as a social system, i.e. an action system characterized by relatively lasting relations of a given kind between the elements of the system. Elements of the system are the general practitioners, the patients and the specialised mental health agencies..