We have designed a compact dual wavelength multi-channel time-resolved system for functional near infrared spectroscopy. The system enables 16 sources and up to 64 collection points, with a minimum acquisition time of 5 ms per channel. Performances of the system have been tested on tissue phantoms in terms of linearity, noise, stability and reproducibility. Preliminary measurements on volunteers have been performed to validate the instrument capability to acquire in vivo maps of the hemodynamic parameters in the muscle during arterial occlusion and in the adult head during a finger tapping experiment.