Patients with overt or resolved hepatitis B virus (HBV) infection undergoing immunosuppressive therapy or chemotherapy for malignant diseases should be screened and monitored for their viral status under the Japan Society of Hepatology Guidelines for the Management of Hepatitis B Virus Infection to prevent the reactivation of HBV. To complete these recommendations, we have adopted a protocol-based pharmacotherapy management for HBV (PBPM-HBV) that allows pharmacists to order additional complementary blood tests on behalf of doctors in our hospital. We also constructed a support system that automatically detects and reports the cases with insufficient examinations by scanning the information of all the chemotherapy patients. By introducing PBPM-HBV, the screening implementation rate was improved significantly from 29.0% to 81.8% (P < 0.001). Also, by utilizing this support system, we were able to achieve remarkable labor and time savings compared to the conventional manual process of checking examination results by opening each electronic medical record. The average time taken to complete the checking process for each patient before and after the introduction of the support system was 1.93 minutes (n = 100) and 0.55 minutes (n = 300), respectively. By utilizing this support system, operating efficiency has been remarkably improved and appropriate HBV screening and monitoring for all cancer chemotherapy patients has become possible regardless of injection or oral administration of the drugs. PBPM-HBV using this support system is considered to be a good example of minimizing the increase in the workload of pharmacists as a result of task shifting from doctors.