In response to the mandate, various Federal agencies in law enforcement, health, and other fields have sponsored data series that contain indicators of the Nation's drug and alcohol abuse problems. While these data collection efforts have generated a considerable amount of information, minimal coordination among agencies has occurred and resulting data are sometimes inadequate or duplicative. In addition, different and seemingly inconsistent findings can be inferred from the data because the various indicator systems are designed for different purposes, focus on different populations, and frequently use different measures of drug abuse problems. Another problem is that many agencies collecting the data have not intended for the information to be widely used outside government. Problems associated with and the potential for existing data to be used more creatively in exploring drug policy issues are analyzed. The following recommendations to improve data systems are offered: systems should accommodate changing information needs and different funding levels, be evaluated for necessary modifications over time, and produce timely output. The use of existing data to support policymaking is discussed, and the need to understand trend dynamics when evaluating the drug-using population is emphasized. Consideration is also paid to the development of a drug surveillance system and to the establishment of a policy framework for identifying data and analysis needs. Appendixes contain further information on ways of improving data and analysis to support national drug policies. References, tables, and figures