Predictors of attrition from individual parent-child interaction therapy were examined for 99 families of preschoolers with disruptive behavior disorders. Seventy-one percent of treatment dropouts were identified by lower SES, more maternal negative talk, and less maternal total praise at pretreatment. Following PCIT, families were randomly assigned to an Assessment-Only or Maintenance Treatment condition. Higher maternal distress predicted 63% of dropouts in the Assessment-Only condition. Lower maternal intellectual functioning predicted 83% of dropouts from Maintenance Treatment. Findings highlight a continuing need for evidence-based retention strategies at various phases of engagement in PCIT.