In team medicine, highly specialized pharmacists have recently been in demand. As one of the specialties, there is therapeutic drug monitoring (TDM). It is important for the optimal dosing of a wide range of drugs. In our hospital, a TDM service was started in 1987 at the clinical laboratory. A clinical laboratory technologist with the license of a pharmacist has performed administration plans for anti-methicillin-resistant Staphylococcus aureus (MRSA) drugs, vancomycin, teicoplanin, and arbekacin. In particular, the pharmacist in charge of TDM services, a TDM-specialized pharmacist, plays a central role in administration plans for anti MRSA drugs. Furthermore, we examined the active use of the TDM service to expand pharmaceutical care. Therefore, at first, we have worked in partnership with the clinical laboratory, as it is called the "Cooperation Support System", since September 2010. As a result, after the introduction of this system, from August 2011 to July 2012, the rate that the doctor referred to the administration plan was markedly improved by approximately 90%. We have been able to enhance TDM in practical training for pharmacology as an extension of this system. We thought that drug therapy can be performed more appropriately by increasing the number of executions of TDM in the future. For drug therapy to be done more appropriately, efforts made through cooperation with the clinical laboratory are essential for an effective TDM system. Naturally, an effective TDM process requires a collaborative, multidisciplinary approach with input from doctors, nurses, and clinical pharmacists.