Previous research into the usefulness of cost-effectiveness information in managed care has had a narrow scope. This research has been limited to the level of importance that managed care directors place on pharmacoeconomic (PE) data, the types of studies that MCOs prefer to review and the future use of this type of information. OBJECTIVES: The purpose of this study was to ascertain (1)the level of importance that PE information has on the speed of formulary approval, (2)the relationship between the cost of therapeutic agents and PE information, (3)the relationship between the time of market entry/number of competitor products and requirements for PE information, and (4)the importance of PE information by therapeutic classification. METHODS: A telephone survey of 41, randomly selected, pharmacy directors and medical directors was conducted to elicit their attitudes towards PE information. RESULTS: PE information was somewhat/very important in influencing the speed of formulary pull-through in 51.2% of respondents. The majority of respondents felt that PE information was not important when drug acquisition cost was less than $100; however, its importance increased as acquisition cost increased. Respondents felt that the time of market entry influenced the level that they placed on PE information. When there were no similar agents on formulary 73.1% felt that PE data was somewhat/very important, when there were ten similar agents on formulary 48.8% of respondents felt that PE information was somewhat not/not important. Respondents indicated that the therapeutic areas of depression, asthma, rheumatoid arthritis, pain control and hypertension were areas where cost-effectiveness analysis would be most useful. CONCLUSIONS: PE information is relevant to managed care decision making and it is influenced by the drug acquisition cost, the number of competitor drugs on market and the therapeutic area under consideration.