Several mediators of the similarity–liking link were examined in a laboratory study that involved previously unacquainted individuals interacting to become acquainted and that also included a preinteraction manipulation of bogus similarity. In addition to replicating the robust finding of a positive association between similarity and liking in both a bogus stranger paradigm and a social interaction paradigm, we tested the roles of five potential mediators of the similarity–liking association: consensual validation, cognitive evaluation, certainty of being liked, fun and enjoyment, and self-expansion opportunity. The results indicated certainty of being liked to be the strongest mediator prior to a live interaction and fun and enjoyment to be the strongest mediator postinteraction. Consensual validation was also found to be a strong mediator postinteraction.