Delinquency reduction and reduction of the number of juveniles referred to the justice system were assessed for 14 diversion programs in Los Angeles County. A project versus nonproject comparison and a pre-post analysis with archival and other data gathered from 1972 through 1977 were used. Preliminary results indicated that the diversion projects may be effective in achieving the objective. Arrest rates were found to be lower after diversion onset for the project areas, but not for the nonproject regions. (Author)