Assessment centers use a simulation approach. Their advantages are their accuracy, the powerful learning experience they provide for both participants and assessors, their acceptance by management, and their appropriateness for minority groups and women. The International Association of Chiefs of Police (IACP) initiated efforts to establish an assessment center in 1970. In 1971 it established a pilot program to assess managerial candidates of the Mississippi Bureau of Narcotics. Since then, the Bureau has used the management assessment process several times. The most important step in establishing the assessment center process is the identification of the specific qualities the agency wants in its managers. The typical assessment center which follows the IACP model uses 2 or 3 days to review 12 candidates for promotion. Police personnel are usually the assessors for the Mississippi Bureau of Narcotics. The candidates assessed as satisfactory have proved to be good managers. The agency has good morale and has increased the seizures of marijuana. Twenty-three reference notes are provided.