This study examined socio-demographic, child, and family-level correlates of retention patterns among parent participants of Familias Unidas/SEPI (Coatsworth, Pantin, & Szapocznik, 2002), a randomized, controlled trial of a family-focused preventive intervention. The current study's aim was to identify variables that could be used to classify ethnic minority (African American and Hispanic) caregivers (N = 143) into their known patterns of retention across 30 sessions of the intervention. Person-centered analyses identified three broad attendance pattern groups: (a) non-attenders; (b) variable-attenders; (c) consistent-high-attenders. Subgroups of the variable-attender group included: (a) dropouts; (b) variable-low-attenders; (c) variable-high-attenders. Four socio-demographic indicators were significant discriminators of the broad retention patterns. Three family-level factors were significant discriminators of the variable-attender subgroups. Additional significant mean/rate differences among retention pattern groups on correlates are reported. Implications for how retention is examined in preventive interventions and for developing intervention strategies for improving retention rates are discussed.