A cross-sectional survey of Ohio hospital formulary systems conducted in the fall of 1982 is presented. The study describes the current status of formulary systems and formularies and analyzes the relationships between structure, process and outcome variables related to formularies and 21 randomly selected Ohio Department of Public Welfare (ODPW) Drug Efficiency Study and Implementation (DESI)-listed drugs. Fifty-five per cent of the state's hospitals reported having a formulary. Hospitals with formularies appeared to have a lower ratio and number of ODPW-DESI agents in stock. However, two variables maximally discriminated the avoidance of ODPW-DESI drugs: 1) the number of drugs in inventory or on formulary, and 2) the existence of a formulary. The results suggest that having a formulary assists in the avoidance of ineffective drug products, but the study's process variables could not predict formulary existence or positive outcomes.