This article includes three studies aimed at adapting the Interpersonal Reactivity Index (Davis, 1980), a measure of general cognitive and emotional empathy, to assess empathy expressed within a romantic relationship. We examined the factorial structure of the Interpersonal Reactivity Index for Couples (IRIC). Results supported the use of the 2-factor measure (Dyadic Perspective Taking and Dyadic Empathic Concern) in 3 independent samples (individuals in heterosexual relationships, individuals in same-sex relationships, and partners of heterosexual couples). The IRIC also demonstrated good convergent, discriminant, concurrent, predictive, and incremental validity as well as adequate internal consistency and stability over 18 months.