Digital telemetry (DT) offers a method of collecting the electrical signals produced by neural activity and transmitting them wirelessly to a receiver/decoder for analysis and storage. The wirelessness means that activity can be recorded from a subject that is behaving relatively normally, which opens up a number of research and therapeutic opportunities - for example, in the study of spatial encoding, or in pre-seizure activity in an epileptic subject. In this chapter we first review the history of neural recording and describe the classic analog method of data processing, outlining the technical problems that need to be solved in collecting and transmitting tiny electrical signals within a noisy environment. We then outline digital signal processing together with the basic principles of telemetry, describing how DT solves these problems in a way that preserves signal fidelity while allowing subjects to move around in an unconstrained way. We finish by describing several situations in which DT is enabling advances to occur both in the laboratory and in the clinic.