The paper presents benefits of optical time-of-flight spectroscopy for medical applications. It also presents the principles of measurement and describes how the basic optical properties of tissue can be estimated from measured data. The potential of time-of-flight spectroscopy is demonstrated, based on measurements conducted for highly scattering materials, such as paper samples, technological liquids from paper mills and aqueous milk solutions. Picosecond semiconductor pulse lasers and fast light detectors (a streak camera and an avalanche photodiode working in Geiger mode) were used. Obtained results show that it is possible to construct a new type of optic fiber sensors for medical applications. The chief advantage of the sensors is their ability to perform measurements in difficult to reach places (e.g. inside human body). Moreover, it is expected that fiber optic sensors based on time-of-flight spectroscopy will significantly reduce the costs of medical diagnosis.