OBJECTIVES: To assess if pharmaceutical care is associated with a decrease in overall health care utilization and cost. Pharmaceutical care entails an expanded role for pharmacists to provide patient counseling and monitoring about medications. Few adequately designed studies have investigated the impact on health care utilization, and, to date, findings are mixed. METHODS: A quasi-experimental design, using utilization/cost data from an HMO database. Intervention sites were 3 staff and 3 contract pharmacies. HMO enrollees with chronic health conditions (lung or heart disease) were identified through the HMO’s electronic pharmacy database. Two years of utilization data (Year-Before and Year-After intervention) were extracted from the HMO database for participants, refusers and controls, excluding people who died, disenrolled, or discontinued their pharmacy benefit. Multiple linear regression analyses were performed with the following dependent variables: difference between Year-Before and Year-After in number of clinic visits, prescriptions dispensed, unique medications, hospital admits, and hospital days, as well as inpatient, outpatient, and total charges. Separate regression analyses were run for 2 models: participants vs. controls and intervention [participants + refusers] vs. controls. Other variables in the regression models were gender, age, Charlson Co-morbidity Index in Year-Before, and group (lung vs. heart disease). RESULTS: Participants were more likely than controls to have an increase in both clinic visits (on average, 1.8 more visits) and prescriptions filled (2.4 more fills). Those in the intervention sample (participants + refusers) were also somewhat more likely than controls to increase their numbers of unique medications (0.6 more). None of the other regression models were significant for the main predictor variables. CONCLUSIONS: Our study does not find that pharmaceutical care decreases health care utilization or cost in this HMO setting. To the contrary, pharmaceutical care appears to be associated with an increase in utilization.