Healthcare and more precisely private hospitals are critical and complex environments where making appropriate decisions is vital. For this reason, they are widely studied in many fields. This paper aims to provide the current state of the art of Digital Twin and/or Simulation involved in Decision Support System (DSS) whose data are processed through Data Mining techniques applied in the healthcare sector. In this view, the authors’ research has been based on the following keywords: Healthcare, Hospital, Digital Twin, Simulation, Data Mining and Decision Support System. Doing so, it has been possible to gather 13 papers which have been carefully studied.