This study investigates the effect of solute additions on electromigration in Al-based thin film binary alloys. The “cross-strip” technique was used to observe solute electromigration and its influence on Al electromigration. The results of electromigration tests on five alloy additions, Ag, Au, Cu, Pd and Ni, are presented. It is concluded that beneficial solutes have two characteristics. First, they have a large, negative effective valence (Z**). Second, they have sufficient solubility in Al at test temperature to provide a reservoir of mobile atoms. Ag and Au are relatively ineffective because of their low effective valence. Pd and Ni appears to be relatively ineffective because of their low solubility at test temperature. Only Cu satisfies both criteria.