The purpose of this study was to describe and evaluate the activities and interventions provided by ambulatory care clinical pharmacists during the IMPROVE (Impact of Managed Pharmaceutical Care on Resource Utilization and Outcomes in Veterans Affairs Medical Centers) study. A total of 523 patients were randomized into the intervention arm at nine Veterans Affairs medical centers if they were considered to be at high risk for drug-related problems. Patients randomized to the control group had no interventions and they are not reported. Using a standard form, pharmacists were asked to document the length of visit, method of contact, medical conditions addressed, and drug-related problems addressed and resolved during each contact. Seventy-eight ambulatory care clinical pharmacists documented 1855 contacts over 12 months, an average of 3.54 +/- 2.31/patient. The length of visits was 15 minutes or more for 73% of contacts. In-person contacts accounted for 1421 visits (76.6%), with the remainder being telephone contacts. During each contact the average number of drug-related problems addressed and resolved were 1.64 +/- 1.16 and 1.14 +/- 0.98, respectively. More drug-related problems were addressed and resolved when visits were 15 minutes or longer (p=0.001) and when the contact was in person (p=0.001). These data may provide information to clinical pharmacists developing pharmacy-managed clinics for patients at high risk for drug-related problems. The information may be a benchmark for types of interventions that can be made, as well as the time commitments required to make them.