This study compared the effectiveness of a culturally modified version of Parent-Child Interaction Therapy (PCIT), called Guiando a Ninos Activos (GANA), to the effectiveness of standard PCIT and Treatment as Usual (TAU) for young Mexican Amerian children with behavior problems. Fifty-eight Mexican Amerian families whose 3- to 7-year-old child had a clinically significant behavior problems were randomly assigned to GANA, standard PCIT, or TAU. All three treatment approaches produced significant pre-post improvement in conduct problems across a wide variety of parent-report measures. GANA produced results that were significantly superior to TAU across a wide variety of both parent report and observational indices; however, GANA and PCIT did not differ significantly from one another. PCIT was superior to TAU on two of the parent report indices and almost all of the observational indices. There were no significant differences between the three groups on treatment dropout, and families were more satisfied with both GANA and PCIT than with TAU.