Demonstrating the value of psychoanalytic theory as a framework, the authors describe in rich detail the evaluation, planning, and carrying out of a successful therapeutic intervention with a ten-month-old infant suffering from a serious psychophysiological disturbance and disordered developmental patterning. They stress the importance of direct observation of the infant and its caretakers and of detailed evaluation of the aspects of caretaking relevant to regulation of tension states. An effective therapeutic plan for an infant must address itself to the characteristics of the multiple stimuli which create the emotional atmosphere of the child's caretaking routines. In addition, it must include attention to the parents in their relationship to each other as well as to their baby.