Upflow moving-bed hydrotreater (MBR) is used in refineries as a guard reactor to a fixed-bed residual desulfurization reactor. Uniform local flow distribution in these reactors is critical to avoid issues like coking, catalyst agglomeration, and hotspots in the catalyst bed. Local maldistribution is investigated on a scaled-down MBR at a scaled-down industrial flow condition using an experimental technique called two-tip optical probe (TTOP), which gives local phase saturations, phase velocities, backmixing, and maldistribution at voids of a two-phase-flow packed bed. TTOP implemented at local radial/axial locations indicates highly fluctuating phase saturations inside the catalyst bed, with zones having low-to-high gas or liquid saturations, indicating severe local maldistribution. The local phase backmixing and local maldistribution is more on the upper part of the bed.