Gold(I)-catalyzed highly regioselective hydration of alkynylsulfones comprises an efficient 100% atom-economic route to β-ketosulfones. The reaction proceeds under mild mercury-free conditions (Ph3PAuNTf2 0.5–5 mol%, THF, rt or 60 °C), it demonstrates a high functional group tolerance (more than 30 examples; yields up to 99%), and can be easily scaled up. The developed hydration methodology was successfully integrated into the one-pot syntheses of valuable heterocycles.