Class of 2008 Abstract / Objectives: To describe a pharmacist-based treatment adherence program at an HIV ambulatory care clinic setting; to describe the patient population that the pharmacist provided services to from 2005 to 2007; and to describe the clinical outcomes of the program. Methods: A retrospective chart review of 381 patients enrolled in the pharmacist-based treatment adherence program from 2/01/05 to 03/01/2007. Inclusion criteria: HIV positive; greater than or equal to 18 years of age; a medical record; and enrollment in the treatment adherence program. The program provided support, education, and clinical management. Results: Patients were predominately male (86%), ages 45-64 (58%) or 25-44 (38%), identifying as Caucasian (57%) or Hispanic (31%), with psychiatric (50%) or substance abuse (39%) comorbidities (with 25% reporting both comorbidities). Baseline HIV viral loads were compared at four different follow-up periods: 90-180 days, 181-365 days, greater than 365 days, and the entire period of follow-up through the pharmacist-based HIV treatment adherence program. At baseline 34% of the patients had an undetectable HIV viral load (< copies/mL) and a mean CD4 count of 340. All follow-up periods reported significant improvements. At follow-up >365 days, 76% of the patients had undetectable virus (p<0.001) and a mean CD4 count of 442 (p<0.001). There were no significant results when viral load and mean CD4 counts were examined within the context of number of pharmacist visits and SA and/or psychiatric comorbidities. Conclusions: Patients in the pharmacist-based treatment adherence program showed significant improvements in CD4 count and percent of patients with undetectable virus from baseline to all follow-up periods. The magnitude of the improvement increased during each follow-up period suggesting an additive effect of continued enrollment in the program.