The author used a mixed methods design to assess field work-related educational disequilibrium and its effect on the self-concept and mental health of MSW students. Twenty-eight advanced, fourth-semester MSW students were compared with 37 entering, first-semester MSW students in practice-related sense of accomplishment. Compared with first-year students, second-year students reported a lower sense of accomplishment, which, in turn, explained their lower self-esteem and higher depressive symptoms. In addition, qualitative data revealed their field work-related struggles with incompetence caused by inexperience. Implications for social work education are discussed. (Contains 6 tables.)