The provision of culturally relevant yet evidence-based interventions has become crucial to global HIV prevention and treatment efforts. In Thailand, where treatment for HIV has become widely available, medication adherence and risk behaviors remain an issue for Thai youth living with HIV. Previous research on motivational interviewing (MI) has proven effective in promoting medication adherence and HIV risk reduction in the United States. However, to test the efficacy of MI in the Thai context a feasible method for monitoring treatment fidelity must be implemented. This article describes a collaborative three-step process model for implementing the MI Treatment Integrity (MITI) across cultures while identifying linguistic issues that the English-originated MITI was not designed to detect as part of a larger intervention for Thai youth living with HIV. Step 1 describes the training of the Thai MITI coder, Step 2 describes identifying cultural and linguistic issues unique to the Thai context, and Step 3 describes an MITI booster training and incorporation of the MITI feedback into supervision and team discussion. Throughout the process the research team collaborated to implement the MITI while creating additional ways to evaluate in-session processes that the MITI is not designed to detect. The feasibility of using the MITI as a measure of treatment fidelity for MI delivered in the Thai linguistic and cultural context is discussed.