Traumatic Brain Injury (TBI) is the leading cause of death and disability in children and adolescents in the U.S. and disproportionately affects young children. The negative consequences of early childhood TBI include deficits in behavior and attention, cognitive abilities, and academic skills. Behavior problems in particular are one of the most common and persistent consequences following TBI in young children. Therefore, interventions are needed that target the adverse effects of TBI on behavior. The purpose of the current work was to examine the initial outcome, feasibility, acceptability, and satisfaction of a time-limited and intensive format of Parent-Child Interaction Therapy (PCIT) for families with a child aged 2 to 5 years who had sustained a TBI and displayed clinically elevated externalizing behavior problems. The open trial included 10 families that completed a baseline assessment, received the intervention over 5 weeks, and completed post-intervention and 2-month follow-up assessments. Results indicated that children who completed the intervention showed significant improvements in both externalizing and internalizing behavior problems at post-intervention and 2-month follow-up, with the exception of non-significant change in self-regulation at post-intervention and 2-month follow-up, and attention problems at 2-month follow-up. In addition, significant improvements were found on all cognitive measures examining working memory, receptive language, and executive functioning at post-intervention and 2-month follow-up. Similarly, caregivers who completed the intervention displayed significant improvements in their parenting skills during play with their child and reported significant reductions in overall caregiver stress and caregiver stress related to their child’s difficult behaviors. Despite limitations inherent in an open trial (e.g., small sample, lack of a control group, generalizability), the current study addressed a relatively unexplored research question and suggests that an intensive format of PCIT may be a promising approach for improving domains commonly affected by early childhood TBI (e.g., behavioral, cognitive, and family functioning) prior to the development of more severe and persistent problems.