A monitoring system is presented for monitoring fluid flow in turbid medium. The fluid flow monitoring system comprises a processor utility which is connectable to an acoustic generator associated with one or more acoustic ports and is operable for generating signals S0 to activate said one or more acoustic ports for irradiating a region of interest with acoustic radiation of a certain frequency range centered at a frequency F0 and is connectable to at least one light output port associated with one or more light detectors for receiving light of at least one wavelength λ from the region of interest including light tagged by said acoustic radiation. In some embodiments, the processor utility is configured and operable for analyzing the generated signals S0 and data indicative of the received light including light tagged by the corresponding acoustic radiation and determining correlation between said signals S0 and said data indicative of the received light, said correlation being informative of a measure of fluid flow in the medium.