This article investigated how relational efficacy affects emotional experiences in romantic relationships. Relational efficacy, which is a shared or intersubjective efficacy expectation of relationship partners, refers to a pair's belief that they can mutually coordinate and integrate their resources to prevent and resolve any problem; this concept is based on social cognitive theory (Bandura, 1997, 2001). Participants were 107 dating heterosexual couples. The results of multilevel structural equation modeling analysis suggested that couples higher in relational efficacy experienced more positive emotions, but not negative emotions. Additionally, it is suggested that partners higher in perceived relational efficacy experienced more positive emotions, but not negative emotions. The implications of the results and their contribution to existing literature are discussed.