The manual outlines a six-stage antigang planning process: preassessment, assessment, development of program goals and objectives, strategy selection, implementation, and monitoring and evaluation. The preassessment, stage 1, prepares correctional staff for the program-design stage. Administrators and staff must determine whether or not a gang problems exists, define what is meant by gang and gang youth behavior, and establish a staff team to conduct the assessment. The assessment, stage 2, develops objective knowledge about the gang problem and the resources of the particular institution available and required to deal with it, including the specific characteristics of gang youths and the problems they are creating in the facility, security requirements, social service needs, the nature of the context of the problem, and the staff capabilities necessary for an effective gang program. Stage 3 of the planning process involves the establishment of program goals and specific long-term and short-term objectives. In stage 4, strategies and procedures are identified to achieve program objectives. Stage 5 comprises detailed planning by the operational units of the facility under the supervision of a central gang coordination unit. This unit should provide policy direction and overall integration of program elements. In stage 6, monitoring and evaluation provide assurance that program strategies and activities are implemented according to design to determine whether or not program objectives are being met and whether the gang problem is being controlled and reduced. Gang program modifications in youth detention centers are also discussed.