Problems of mental retardation and mental illness are prevalent among prison populations. One research study concluded that approximately 10 percent of the inmate population is mentally retarded. The marked increase in prison populations has aggravated the situation. In addition, distresses and violence that characterize prison life contribute to mental difficulties. A minimum constitutional standard for prison medical care has evolved largely in the past decade. In 1976, the Supreme Court ruling in Estelle v. Gamble articulated the consensus standard for correctional institutions. Nevertheless, general health care in prisons is often inadequate, and mental health services are usually one step below the standard health care. Inadequate facilities and staffing are the major causal factors. The staff/inmate ratios for various treatment professionals in State adult institutions is 1:521 for psychologists and 1:676 for psychiatrists. Part-time professionals tend to rely on the permanent staff person who has major supervisory authority in the mental health area. In addition, communication is a problem, especially since few minority mental health professionals are employed in the Nation's corrections facilities. The transfer of inmates from correctional to mental health facilities has caused the most litigation. In the 1966 case of Baxtrom v. Herold, the Supreme Court ruled that the transfer which was effected while the inmate was serving his sentence was in violation of the equal protection clause of the 14th amendment. Nevertheless, questions remain about due process rights attendant upon transfer. A table showing statutory provisions for prison to mental health facility transfers and 93 reference notes are provided.