Psychosocial interventions for atypical depression (AD) have been relatively ignored in the clinical research literature, despite evidence that the atypical subtype of major depression is marked by earlier age of onset, longer duration of mood episode, greater symptom severity, and poorer response to pharmacologic treatment. Given the symptom profile of AD, which is characterized by mood reactivity, psychomotor slowing, and interpersonal withdrawal, the authors argue that a behavioral activation (BA) intervention may be particularly well suited to this population. As an initial exploration of this hypothesis, the current study presents preliminary outcome data from 10 outpatients with AD who participated in an open pilot trial of BA over a 16-week period. Overall, results provide encouraging preliminary support for the feasibility, acceptability, and efficacy of BA for AD, with significant reductions in depressive symptoms and associated improvements in functional impairment and BA level. Study results are discussed in the context of existing treatments for AD, and areas for future treatment development are highlighted. (Contains 2 tables.)