<p>Objective: Pharmacists in inpatient pharmaceutical services are required to evaluate the medications that patients bring with them to the hospital when admitted and to make recommendations to physicians about these medications' proper use. Many hospitals perform such inpatient pharmaceutical services. Studies have found that pharmacists with insufficient years of experience are often put in charge of this practice. This has resulted in patients continuing to take inappropriate medications. We hypothesized that the involvement of another pharmacist in checking outpatient medications brought to the hospital might lower the rate of inappropriate use. We initiated the rechecking of medications brought to the hospital by the drug information (DI) pharmacist, based on the need for cooperation between the DI pharmacist and ward pharmacists.</p><p>Methods: We initiated rechecks by DI pharmacists of medications brought to the hospital and first checked by ward pharmacists, and estimated the medical economic impact of pharmaceutical intervention between 1 May 2019 and 30 April 2020.</p><p>Results: Within one year, the DI pharmacist suggested 15 interventions, including four interventions related to digitalis products and three related to direct oral anticoagulants. The medical economic impact was estimated to be 10,175,000 yen.</p><p>Conclusion: Our findings suggest that checking by another pharmacist of outpatient medications brought to the hospital is a useful addition to the check by ward pharmacists.</p>