Federal, State and local governments have begun to contract with private firms for the operation of prisons and jail research has shown that such contracts can significantly reduce costs. Comparisons of the quality of private versus public prisons have been more difficult to make. In a study of three women's prisons, one private, one Federal, and one State run, eight dimensions were identified to define quality of confinement: security, safety, order, care, activity, justice, conditions, and management. Using prison records and surveys of staff and inmates, 333 empirical indicators were identified for each dimension. (Only 131 of these indicators were available for the Federal prison.) A Prison Quality Index was then calculated for each prison. The private prison outperformed the State and Federal facilities in all but two dimensions: care, where the State prison slightly outscored the private prison, and justice, in which the Federal and private prisons achieved equal scores. 2 tables, 2 figures, 1 appendix