Pharmacists should play an important role in controlling the pharmaceutical management of the patients. Although the quantitative evaluations of pharmaceutical management are required systematically, no guideline is presented for patient care during lung cancer chemotherapy. We established a complete pharmaceutical management system and evaluated the performance of the system. Patients admitted to Hokkaido Keiaikai Minami-ichijo Hospital for lung cancer chemotherapy treatment from 2003.5 to 2003.11 were enrolled in this study after signing formal written consents. The pharmaceutical management system that was established involves a unified system consisting of a standard care plan and worksheets by the Problem Oriented System (POS). The system can apply to inpatients for their comprehensive evaluation of pharmaceutical management. The incidence of pharmaceutical problems reported, pharmacist interventions to the physicians, and the bedside pharmaceutical management were increased significantly after applying the system. More than 98% acceptance of interventions by pharmacists to the physicians was indicated. A high rate of intervention for adverse drug reaction (ADR) was demonstrated, due to the information about patient conditions is essential in managing ADR. The total pharmaceutical management system established is expected to give quality improvements of pharmaceutical care along with its efficiency.