A low frequency AC electromagnetic tracking system is presented that is capable of determining the position and orientation of a catheter tip. Advantages of using magnetic tracking for this application is that magnetic fields are non-ionizing and pass through the human body with minimal attenuation. Low frequency fields are used to mitigate the effects of eddy currents induced in conductive materials found in the environment. There are two significant differences between this and other magnetic tracking technologies, these being (1) the use of a single magnetic sensing coil for position and orientation determination and (2) the eliminating of range restrictions between the sensing antenna and the magnetic field generators. This paper will discuss the general theory of electromagnetic tracking, why it is that researchers have an intense interest for internal tracking and a comparison of the new and old tracking technologies. Some applications of this tracking technology will also be presented.