Countertransference is an important aspect of the therapeutic relationship that exists in therapies of all theoretical orientations and depending on how it is managed, it can either help or hinder treatment. Management of countertransference has been measured almost exclusively with the Countertransference Factors Inventory (Van Wagoner, Gelso, Hayes, & Diemer, 1991) and its variations, all of which focus on 5 therapist qualities theorized to facilitate management: self-insight, conceptualizing ability, empathy, self-integration and anxiety management. Existing versions of the Countertransference Factors Inventory, however, possess certain psychometric limitations that appear to constrain how well they assess actual management of countertransference during a therapy session. We thus sought to develop a new measure that addressed these limitations and that captured the 5 therapist qualities as constituents (rather than correlates) of countertransference management that manifest in the treatment hour. The development and initial validation of the resulting 22-item Countertransference Management Scale (CMS) is described here. Exploratory factor analysis of ratings of 286 therapy supervisors of current supervisees indicated that the 5 constituents of countertransference management could be grouped into 2 correlated factors: "Understanding Self and Client" and "Self-Integration and Regulation." Evidence of convergent and criterion-related validity was supported by CMS total and subscale scores correlating as expected with measures of theoretically relevant constructs, namely, therapist countertransference behavior, theoretical framework, self-esteem, observing ego, empathic understanding and tolerance of anxiety. Results also supported the internal consistency of the CMS and its subscales. Research, clinical and training implications are discussed.