Blue emitting CaWO4 and greenish blue emitting ZnWO4 nanoparticles are synthesized via microemulsion techniques applying a cationic (CTAB) as well as a non-ionic surfactant (TritonX-100). The influence of the surfactant on particle size and shape is studied. Scanning electron microscopy and dynamic light scattering confirm the presence of uniform and non-agglomerated nanoparticles, 60-80 nm in diameter. Photoluminescence confirms [WO4](2-)-related broad-band emission with its maximum at 440 nm (CaWO4) and 420 nm (ZnWO4). The highest quantum yield (QY) is observed for nanoscaled CaWO4 with a value of 23-25%. Doping of CaWO4 and ZnWO4 with Tb3+ and Tb3+ was performed and in the case of CaWO4:Tb and CaWO4:Eu and results in the emission of green and red light, again with comparably high QYs (17-19%).