Based on the psychoanalysis of adults with borderline and narcissistic personality disorder symptoms, Kohut ( 1971 , 1977, 1980, 1984) formulated a theory of self psychology that emphasized the importance of early developmental experiences; most centrally, the empathic attunement of caregivers as key ingredients for fostering the capacity for healthy self-regulation and interpersonal relations. Kohut elaborated 3 critical selfobject needs (i.e., idealizing, mirroring, and twinship) that were ideally satiated by these early experiences, deeming the fulfillment of these needs as essential for developing a healthy sense of self. The research presented here sought to develop a self-report measure, titled the Arble Estimate of Selfobject Pursuits (AESOP), capable of assessing the selfobject needs identified by Kohut. Across 2 studies involving 686 and 672 respondents, participants completed the AESOP. In the first study, an exploratory factor analysis supported the theorized 3-factor structure. In the second study, a confirmatory factor analysis indicated adequate-to-strong model fit and cluster analysis with theoretically related measures supported the AESOP's discriminant and convergent validity. Further research is encouraged to elaborate the implications of these preliminary findings.