Various findings of the Impact of Managed Pharmaceutical Care on Resource Utilization and Outcomes in Veterans Affairs Medical Centers (IMPROVE) study are reviewed. Suggestions for future methodologies that will enhance this study are discussed. The IMPROVE study is one of the largest pharmaceutical care studies conducted. Although it was an intervention study that examined global outcomes following management by pharmacists, it was designed as an effectiveness study. Several new practice and research methods were developed, including a method to identify patients at high risk for drug-related problems utilizing pharmacy databases, a method to identify chronic diseases using pharmacy databases, a method to evaluate the structure and process for delivering pharmaceutical care in Veterans Affairs medical centers (VAMCs), and guidelines for providing care to patients in the IMPROVE study. Nine VAMCs participated in the study, and 1054 patients were randomized to either an intervention group (n = 523) or a control group (n = 531). Pharmacists documented a total of 1855 contacts with the intervention group patients and made 3048 therapy-specific interventions over the 12-month study period. There was no meaningful difference in patient satisfaction or quality of life in the two groups. Selected disease-specific indicators found an improved rate of measurement of hemoglobin A1c tests and better control of total and low-density-lipoprotein (LDL) cholesterol levels in the intervention group compared with the control group. Total health care costs increased in both groups over the 12-month period. The mean increase in costs in the intervention group was $1020, which was lower than the control group's value of $1313. The lessons learned from the IMPROVE study suggest to future investigators how to study and measure the effects of clinical pharmacy services on patient outcome.