The treatment of incarcerated batterers has not been as thoroughly studied as that of men who take part in community treatment programs. The current study describes and analyzes the "practice wisdom" of professionals in a special unit that focuses on treating batterers in an Israeli prison. The analysis is based on in-depth semistructured interviews aimed at facilitating a self-reflective process among the participating social workers. In understanding the construction of tacit knowledge by the social workers, we observe four major dialectical themes in their construction of their practice knowledge: (a) the dialectics of behavior modification and psychodynamic change, (b) the paradoxical use of authority in the service of treatment, (c) the multiple meanings of gender, and (d) the question of change—what really makes the difference? While such opposites might never be fully reconciled, the tension and changes can contribute to construction of professional knowledge.