The term ?social psychiatry? became current in the Netherlands from the late 1920s. Its meaning was imprecise. In a general way, the term referred to psychiatric approaches of mental illness that focused on its social origins and backgrounds. In this broad interpretation social psychiatry was connected to the psycho-hygienic goal of preventing mental disorders, but also to epidemiological research on the distribution of mental illness among the population at large. The treatment called ?active therapy?, introduced in Dutch mental asylums in the 1920s and geared towards the social rehabilitation of the mentally ill (especially through work), was also linked with social psychiatry. In a more narrow sense social psychiatry indicated what before the 1960s was usually called ?after-care? and ?pre-care?: forms of medical and social assistance for patients who had been discharged from the mental asylum or who had not yet been institutionalized. This article focuses on the twentieth-century development of Dutch social psychiatry in this more narrow sense, without, however, losing sight of its wider context: on the one hand institutional psychiatry for the insane and on the other the mental hygiene movement and several outpatient mental health facilities, which targeted a variety of groups with psychosocial and behavioural problems. In fact, the vacillating position of pre- and after-care services was again and again determined by developments in these adjacent psychiatric and mental health care domains. This overview is chronologically divided into three periods: the period between and during the two world wars, when psychiatric pre- and aftercare came into being; the post-Second World War era until 1982, when the Social-Psychiatric Services expanded and professionalized; and the 1980s and 1990s, when they became integrated in community mental health centres.