It is well documented in the literature that child sex trafficking can be perpetrated by family members, though limited research has focused on describing this type of sexual exploitation. This pilot study addresses this gap by providing an analysis of familial sex trafficking considering trafficking dynamics, and rurality. Using a sample of 31 child welfare-involved children referred for behavioral health assessment and treatment, this mixed methods study explores: (1) victim and trafficker characteristics, the trafficking situation, law enforcement classifications of trafficking, clinical profiles of victims, and system involvement of children and youth involved in familial sex trafficking; (2) gender differences in clinical outcomes in sex-trafficked children; and (3) geographical differences in severity of the victimization experience. Major findings document high rates of family members trafficking children for illicit drugs; high severity of abuse as measured with the Sexual Abuse Severity Score, with higher severity of abuse for children living in rural communities; clinical threshold level scores on the Child Behavior Checklist (CBCL), and the Trauma Symptom Checklist for Children (TSCC-A). Boys and girls had similar clinical profiles except boys had higher CBCL externalizing scores, and females had higher TSCC depression scores. Additionally, more than half of the children in this sample had attempted suicide in their lifetime. This formative study sheds light on the phenomenon of familial sex trafficking, thereby creating the context for further investigations. Implications for identification and effective responses to familial sex trafficking, with specific attention to gender and geography are discussed.