Ytterbium-doped tungsten tellurite glasses have been prepared and studied their cooperative upconverted luminescence and radiative energy transfer properties. In a 3.0mol% Yb2O3-doped glass, near-infrared emission band is peaked at around 977nm with a full width at half maximum of around 15nm. This glass emits blue–green upconverted emission under 980nm excitation due to cooperative processes involving two interacting Yb3+ ions. The upconverted emission band is centered at around 502nm with a bandwidth of around 45nm. Power dependence of cooperative emission intensity and the temporal evolutions of the near-infrared and blue–green emissions confirm the presence of cooperative luminescence. Photoluminescence and lifetimes have been measured by moving the laser excitation from one edge of the sample and found that radiative energy transfer is predominant in 3.0mol% of Yb2O3-doped glass. The absorption coefficient obtained from absorption spectrum is in good agreement with that obtained by fitting the curve of luminescence intensity versus distance from the edge of the sample.