This study built a protocol for drug therapy management (hereinafter “the protocol”) that would enable continuous support from the decision making of smoking cessation therapy to the completion of therapy through the collaboration of physicians and community pharmacists, after which we evaluated whether the use of this protocol would be helpful to smoking cessation therapy. This study utilized the “On the Promotion of Team-Based Medical Care”, a Notification by the Health Policy Bureau as one of the resources for judgment, and referred to collaborative drug therapy management (CDTM) in the United States. After the implementation of this protocol, the success rate of smoking cessation at the participating medical institutions rose to approximately 70%, approximately 28-point improvement compared to the rate before the implementation. In addition to the benefits of the standard smoking cessation program, this result may have been affected by the intervention of pharmacists, who assisted in continuing cessation by advising to reduce drug dosage as necessary approximately one week after the smoking cessation, when side effects and the urge to smoke tend to occur. Additionally, the awareness survey for the intervention group revealed that all respondents, including patients who failed to quit smoking, answered that they were satisfied to the question on general satisfaction. The question about the reason for successful cessation revealed that the support by pharmacists was as important as, or more important than, that by physicians and nurses. This infers that the pharmacists' active engagement in drug therapy for individual patients was favorably acknowledged.