In this study, we have developed a non-contact temperature sensor using a silver halide optical fiber for medical endoscopic usage. We have measured an infrared radiation which is transferred by a silver halide optical fiber from a heat source using a thermal optical power-meter and a thermopile sensor. To increase the amount of infrared radiation through the silver halide optical fiber and to the infrared sensors, optical devices such as an infrared collimator and a focusing lens are used. The relationships between the temperatures of a heat source and the measured output signals are determined. The measurable temperature range of a fiber-optic temperature sensor is from 30 to 60degC. It is expected that a non-contact temperature sensor using an infrared optical fiber can be developed for medical and industrial usages based on the results of this study.