The VISTA Kilo-Degree Infrared Galaxy Survey (VIKING) survey provides an important complement to the optical KIDS project. VIKING will image the same 1500 square degrees of the sky in Z, Y, J, H, and Ks to a limiting magnitude 1.4 mag deeper than the UKIDSS Large Area Survey. The near-infrared data will be used in the determination of very accurate photometric redshifts, especially at z>1, an important step in the weak lensing analysis and the observation of baryon acoustic oscillations. Other science drivers include the hunt for high redshift quasars, galaxy clusters, and the study of galaxy stellar masses.