OBJECTIVES: The objective of this study was to establish current practice in TDM in K-Tx in a real-world clinical setting, and to develop a best-practice concept to improve patient care. METHODS: TDM processes for transplanted patients were collected at 13 centers in 5 countries between January 2015 and June 2015. More than 35 Interviews with physicians, nurses and lab assistants were combined with observation of relevant steps during standard examination sessions. Duration of each main step to adjust the patient medication dose was recorded. Also dependencies from outside variables were recorded. RESULTS: Several process patterns were identified. Main observed differences among centers were process steps and inefficiencies in exam setup and time required getting test results. The time gap between taking blood samples and availability of results leads to long patient stay and/or multiple visits or contacts with the patient (blood test, examination, result communication). Average time for patients in a center was 2:12 hours with a large range from 0:49 hours to 6:22 hours. Process time for blood drawing, examinations and results communication (excluding lab processing) was on average 30 min ranging from 12 min to 52 min. Complexity and time to get the results could be improved if a near-patient-test (NPT) scenario would be available while others are subject to normal process improvements. CONCLUSIONS: Results suggest that improvements could be made in all types of scenarios. Especially fast availability of test results in a NPT scenario could reduce complexity and facilitate the development of an improved process setup.