The spectroscopic characterization and fluorescence dynamics of Yb<sup>3+</sup>:LiLa(WO<sub>4</sub>)<sub>2</sub> crystal are investigated. The Yb<sup>3+</sup>:LiLa(WO<sub>4</sub>)<sub>2</sub> crystal exhibits a broad absorption and emission spectral bands, large absorption and emission cross sections, and moderate fluorescence lifetime. Blue light emission around 480 nm is observed at 10 K and is demonstrated through cooperative upconversion from the deexcitation of excited Yb<sup>3+</sup>-Yb<sup>3+</sup> pairs.