The U.S. Parole Commission uses the salient factor score as an aid in assessing an offender's likelihood of favorable outcome upon release. The most recent revision of the score became effective in April 1977. The instrument contains seven items: prior convictions, prior commitments, age at first commitment, whether the commitment offense involved auto theft or checks, whether parole had ever been revoked or the inmate is a probation violator, history of opiate dependence, and verified employment or full-time school attendance for at least 6 months during the last 2 years in the community. A total score ranging from 0 to 11 points is assigned; the higher the score, the higher the probability of favorable outcome upon release. The informational base for the construction of the salient factor score was obtained through the analysis of a random sample of 2,497 Federal prisoners released in 1970. An additional random sample of 2,149 prisoners released during 1971-1972 provided the informational base for validating the device. The types of release covered include parole, mandatory release, and expiration of sentence. The first measure of recidivism defines favorable outcome as no arrest for a new criminal offense resulting in a conviction and commitment of 60 days or more and no return to prison as a result of a violation of the terms of release. The second measure defines favorable outcome as no arrest for a new criminal offense (regardless of disposition) and no return to prison as a result of a violation of the terms of release. Each of the seven items in the salient factor score was found to be significantly associated with each measure of favorable outcome, although the items were more significantly related with the first measure. Data tables, footnotes, a list of definitions, and appendixes containing a score sheet and decisionmaking guidelines are included.