While it is generally acknowledged that imprisonment is one of the severest sanctions the criminal justice system can impose, little attention has been given to the practical deviation in the pain of confinement due to varying conditions between prisons. An index of incarcerative conditions provides not only the vehicle for summarizing an extensive array of data and providing a baseline against which future data can be measured, but also provides a mechanism of systematic sampling of certain 'social aspects' of prison communities. The index constructed is based on the measurable criteria of density and occupancy, the level of deviance within the facility, freedom of movement, access to services, and expenditures per inmate. Density and occupancy are measured by the number of inmates occupying less than 60 square feet and the number in multiple housing. Level of deviance is determined by the number of inmates subjected to disciplinary action and protective custody, while freedom of movement is measured by the number of hours inmates are confined and the number in maximum security. Access to services is determined by the number of service providers and the ratio of inmates to service providers. Expenditures per inmate consist of the direct cost per inmate per year. Eight States were selected for analysis, two from each of the four major census regions--New Mexico, Oregon, North Carolina, Florida, Massachusetts, Pennsylvania, Minnesota, and Illinois. Results show that confinement conditions vary greatly across States, across facilities thought to be similar in size and offense distribution, and within States. Tabular data and 19 references are provided.