In recent years, there has been much discussion of the efficacy of mental health interventions for children as well as the transportation of empirically-supported treatments (ESTs) to field settings. A logical initial step in this line of research is to examine whether the efficacy of ESTs can be demonstrated in community settings such as in the home environment. The purpose of the study was to examine the efficacy of an in-home Parent-Child Interaction Therapy (PCIT) program using a single-subject, A/B design across five subjects with staggered baselines. Decreases in caregiver use of negative behavior and caregiver-reported child behavior problems were observed for the three families that completed treatment. In addition, completers demonstrated increases in child compliance, caregiver use of positive behavior, and contingent praise. Data regarding caregivers' reported parenting stress and caregiver proportion of direct commands were less convincing. All three dyads completing treatment reported satisfaction with the intervention. Clinical implications regarding the possible benefits of PCIT for improving the effectiveness of home visiting programs are discussed as well as directions for future research. (Contains 2 tables and 6 figures.)