The role of cost- and pharmacoeconomic-related criteria in formulary decision-making was assessed in a literature review of 31 studies of hospital (n=18) and managed care (n=13) pharmacy and therapeutics (P&T) committees. In both settings, cost was important, although the elements of cost considered varied. Acquisition cost was mentioned more frequently than pharmacoeconomic or cost-effectiveness information. Other factors, including drug characteristics, quality of life, supply-related issues, and physician demand, also influenced decisions. Despite the relatively low reported usage of pharmacoeconomic data in decision-making, most respondents considered the information to be "somewhat" or "very" important. Barriers to the use of pharmacoeconomic information included institutional factors and lack of training. Limitations in the survey methods used and issues considered restricted the ability to identify a comprehensive and consistent role for cost information in selecting formulary drugs. Further research on the use of pharmacoeconomic information is required.