Evidence-based interventions for infants and preschoolers, and their families, have largely focused on the mother-child dyad. In response to the increasing need to diversify treatment approaches in the under six population and include the whole family system, we have developed a new treatment approach called Reflective Family Play (RFP). A manualized, whole-family therapy, RFP allows for the involvement of two parents and siblings when working with infants or young children. In this case-series, we used a qualitative chart review to examine the therapeutic process, acceptability, and feasibility of RFP for 22 families with children ages 0–6, who participated in RFP. We also sought to better understand the referral characteristics of those families who participated in RFP by comparing them to families who were referred to and participated in an established dyadic approach during the same time-period. Session-by-session coding of clinician chart notes revealed evidence of positive shifts throughout the RFP process, including more whole-family play, improvements in coparenting, and better parental mentalization. Parents reported improvements in presenting concerns in all but one case. Improvements in coparenting, sibling relationships, and family alliance were also reported by parents after RFP. Clinical implications and directions for future research are discussed.