The last ten years have seen a rapid growth in the use of the telephone as an educational medium. The development of distance education systems, the growth of continuing education programmes for adults, increases in the costs of travel, and new technological developments, have all combined to point to the telephone as a potentially powerful educational tool. During the last decade, teaching by telephone has been used in a number of distance education contexts, and in a variety of ways, with individuals, and with small and large groups. This chapter will, briefly, describe how telephones are used for teaching, examine the technology and the costs involved, and discuss its effectiveness as a teaching/learning medium.