This study evaluated the cross-cultural transportability of motivational interviewing (MI), an evidence-based addiction treatment method. Free clinical training in MI was offered in separate targeted workshops for 86 African American, Native American, and Spanish-speaking addiction treatment providers. Audiotaped pre- and posttraining clinical work samples were coded for indexes of MI competence. In all 3 samples, posttraining gains in MI proficiency were at least as large as those found earlier with predominantly non-Hispanic White providers. Combined with evidence for the efficacy of MI in minority populations, these findings support the cross-cultural applicability of MI. (Contains 3 tables.)