A review of the history of prison violence shows it is not a recent phenomenon, although its elements and characteristics have undergone considerable change. An examination of official reports and the literature on the causes of prison riots reveals a consistent group of causes: poor food service, overcrowding, excessive size and obsolete physical plants, insufficient financial support, lack of professional leadership, substandard personnel, inhumane prison administration, staff brutality, inadequate treatment programs, idleness and boredom, political interference with personnel and programs, and groups of unusually refractory hard-core inmates. Some recent studies include conspiracy theories which attribute etiologic significance to agitators both inside and outside the prison. Social organizational characteristics of the prison which are important but not sufficient causes of prison disorders include (1) the prison as a solitary-opposition social system; (2) racial, political, and ideological tensions in the prison; (3) relative deprivation; and (4) the prison as a mixed-goal institution of treatment and custody. An analysis of the riots in three Michigan prisons indicates that beyond the usual causes of prison riots, a critical factor is the presence of anomie in the prison system. An anomic correctional system has a state of powerlessness or a power vacuum that inmates rush to fill. While prison conditions experienced by inmates are important factors in diminishing or enhancing riots, developments outside the prison have a profound effect on the inmates, as they follow what is happening in the courts and the legislative and executive government branches. Both microsystemic and macrosystemic factors must be considered in the development of conditions conducive to the prevention of prison disorders. Forty-four bibliographic entries are provided.