Fiber optic probes for a small portable reflectance spectrophotometry system for noninvasive clinical diagnosis have been developed. A slender fiber optic probe, 3 m long, 2.4-mm diameter, which goes into the channel of a fiber optic endoscope, has been developed as the standard probe. To expand the availability and capability of this reflectance spectrophotometry system, some variations of the fiber optic probes were developed: contact sensor, pressure sensor, attachments for dental use, and a modified-shape probe head for continuous monitoring. The feasibility of these fiber optic probes was examined experimentally.