This invention relates to a process for the catalytic hydrogenation of impurity laden methylenedianiline feedstocks commonly referred to a MDA-50 and MDA-60. The process for hydrogenating methylenedianiline containing at least 40% oligomer function by weight comprises: contacting the feedstock with hydrogen in the presence of a rhodium/ruthenium containing catalyst system carried on a lithium aluminate support under conditions for effecting ring hydrogenation.