Dissolving metal reductions of carbonyl compounds is a very attractive procedure.  Many metals, such as Li, Na, Mg, Ca, In, Zn and Al in the presence of different solvent compositions can be used for this purpose.  In this paper, we describe samarium metal-induced reductive dimerization of different types of aromatic ketones in the presence of additives.  Clearly, samarium in the presence of ammonium chloride/bromide in aqueous methanol is the best reagent identified for this purpose.  Water in combination with these salts has an important contribution in accelerating the reaction.  From a detailed study, it is realized that the best yield could be obtained when the proportion of methanol and water is kept 9:1 or 8:2.  A most probable mechanism has been advanced to explain the diastereoselectivity of this dimerization reaction.  Summarizing the results on the diastereoselectivty (dl and meso), a hypothetical transition state model has also been proposed.