In order to assess the characteristics and influence on healthcare decision making of the economic assessment of drugs in Spain, pharmacoeconomic studies carried out between 1982 and 1992 were examined. We identified and analysed 16 pharmacoeconomic studies. The commonnest type of economic assessment was cost-effectiveness analysis. Only one study included measures of health-related quality of life. Only one study was carried out in conjunction with a controlled clinical trial. Evidence of influence on decision making was found in 6 studies. Two studies implemented hepatitis vaccination programmes, one set up a telephone follow-up of antituberculosis chemoprophylaxis, one developed the official procedures for using epoetin (recombinant human erythropoietin), one initiated clinical discussion meetings about the cost effectiveness of cholesterol-lowering therapy, and one strengthened the decision to register nebacumab (HA-1A, Centoxin), the monoclonal antibody against endotoxin. The quality of the studies was acceptable according to generally agreed checklists, although somewhat lower than those in other countries with longer traditions in this field. Improvement of the scientific quality of the studies and an increased use of the results for decision making need to be promoted. At present the number of studies of economic assessment of drugs in Spain is low, as is the influence of these studies on healthcare decision making. The movement of the Spanish healthcare authorities towards a selective drugs funding policy is likely to increase the number of studies and their impact on healthcare decision making.