OSL and TL in some Cu doped alkali fluoro-silicates were studied. These investigations show that the materials possess good OSL properties and the sensitivity is comparable to that of the commercial a-Al₂O₃:C phosphor. Of the several fluoro-silicate phosphors studied Cu doped Na₂SiF₆ is found to be highly sensitive. The initial OSL intensity averaged over first second using blue and green light stimulation, were found to be 1.2 and 13.3 times respectively of Al₂O₃:C. The simple preparation procedure, high OSL sensitivity, fast decay, and high photoionization cross-section will make these phosphors suitable for online radiation dosimetry, particularly in medical dosimetry applications.