A three-channel biotelemetry system measuring ECG, respiration, and body temperature is described. The transmitter employs a 6-kHz subcarrier oscillator and is small enough for surgical implantation in animals the size of rats or larger. The frequency modulated 6-kHz tone from the reciver can be demodulated directly or recorded on an inexpensive cassette tape recorder for future analysis. The transmitter cost is approximately $35.00 and measures 3 times 1 cm. A battery life of several weeks and transmitter range of 10-100 m is typical. Transmission is on the FM broadcast band (88-108 MHz) and reception from an inexpensive FM portable receiver is possible.