Immediate, brief therapy in walk-in clinics is emerging as a major treatment modality for socioeconomically deprived patients. A variety of techniques may be used, such as verbal psychotherapy, medication, and environmental modification, and it is often difficult to select the appropriate method for the particular case. A model is presented that helps to systematize the evaluation procedure. A psychiatrist-social worker joint initial interview leads to a dynamic formulation and to an action formulation, which focuses the data on one of four “levels”: situational variables, ego functions, emotional conflicts, or character. The level chosen determines the intervention tactics.