Between January 1, 1985, and January 1, l986, Missouri's protective custody (PC) inmate population increased from 4.7 percent of inmates to 11.7 percent of inmates, making this a problem that must be addressed. Missouri's policies and procedures for protective custody do not differ substantially from those in the other States examined. PC inmates generally have more physical, intellectual, and psychological deficiencies than the average inmate in the general population, perhaps making them more vulnerable to harm from other inmates. PC does little to help remedy these deficiencies. Some short-term recommendations for reducing the PC population are to increase the use of transfers in lieu of PC, take steps to reduce overclassification that leads to PC, and allow transfer to PC at lower custody institutions for those who qualify. The major recommendation is that an intra-classification system be tested in a pilot program along the lines suggested by Herbert Quay. This would provide for regimes designed to meet inmate needs, including personal safety, without resorting to PC. The study recommends that a pilot program be established and evaluated to test the system. 36 tables, 16 references, and a list of survey respondents.