Real time location systems (RTLS) are being used more and more in healthcare systems for a variety of purposes, such as to track assets, patients, physicians, nurses and staff. Since not much is known about the state-of-art of this emerging field, we summarize best practices for how healthcare systems are using RTLS technology as well as potential systems engineering research issues in this area. We review the general use of RTLS, how it has been applied in healthcare, benefits and challenges of using RTLS, and opportunities. Three potential uses of RTLS are to provide better reference data for historical analysis, a basis for better parameterizing existing models, and for developing new types of models altogether. RTLS provides real time data describing the position and condition of specified objects and people.