Behavioral family interventions are an effective way to intervene to prevent negative developmental outcomes for adolescents. Participation in family interventions encompasses behavioral and cognitive/attitudinal dimensions, among others, indicated by retention and engagement, respectively. Two dimensions of participation, retention and engagement, in a family intervention were examined in a sample of newly homeless adolescents and their parents or guardians. Correlates of participation included parents with more income and less perceived family conflict and adolescents with higher endorsement of depression, anxiety, somatization, obsessive-compulsive, phobic, and psychotic symptoms on the Brief Symptom Inventory (BSI). Stronger therapeutic alliance was correlated with being more distressed (i.e., lower income, more hostility), being a female adolescent participant, and having greater comfort discussing sex with parents. Furthermore, parents and adolescents with greater distress and thus greater need were more apt to finish the intervention. The finding that families who were experiencing more distress had higher alliance scores suggests that there is an additional need for development of interventions for families in crisis. Both participant and provider perceptions are also important in development of a strong therapeutic alliance. This study's findings have implications for further exploration of the development of cultural humility and improving mental health literacy among facilitators of behavioral interventions.