The present study investigated the psychometric properties of the NEO Five-Factor Inventory (NEO-FFI) Observer form of the five-factor model of personality by examining agreement between self- and observer ratings. Both partners of 49 young, adult couples rated themselves and their partners on the NEO-FFI. The results provide preliminary evidence of the measurement utility of the NEO-FFI Observer form. Specifically, (a) each personality scale possessed acceptable levels of internal reliability, (b) five factors consistent with the five-factor model of personality emerged in both ratings forms, and (c) there was significant self-observer agreement for all five personality scales. Self-observer agreement was assessed by correlations as well as analyses that test a more stringent definition of agreement. Overall, there is consensus across analyses that points to a substantial amount of concordance between partners' self- and observer ratings.