This paper looks at the processing of multidimensional bandlimited signals which have been sampled on hexagonal lattices. The hexagonal sampling theorem and its attendant aliasing are reviewed and algorithms for digital filtering and interpolation between hexagonal and rectangular lattices are presented. The efficiency of these procedures is discussed. The hexagonal lattice is shown to possess some definite advantages compared to the rectangular lattice with respect to computational complexity, particularly for isotropic systems. These advantages, however, probably do not outweigh the need for interpolation on data which has already been sampled on a rectangular lattice.