Efficient communication is crucial in mental healthcare, where language often constitutes the chief means of treatment. In intercultural counseling sessions, communicating with Limited English Proficient (LEP) clients calls for skillful collaboration with language interpreters. However, best practices in medical interpretation may not be equally efficient in mental health settings. This inquiry explored the factors fostering and impeding successful communication during interpreter-mediated counseling sessions with LEP Bhutanese and Iraqi refugee men. Researchers observed eight substance use counseling sessions in real-time to make note of communication patterns and key communication breakdowns. Then, researchers conducted video-elicitation interviews with the client, clinician and interpreter immediately after each session to dissect communication events from each party’s viewpoint. Session videos and interview transcripts underwent qualitative assay to distinguish factors that forecast or impede communication breakdowns. Findings point out notable differences between mental health interpretation and interpretation in other healthcare settings. Common practices like simultaneous interpreting and first person interpreting were found to operate differently in a mental health setting. Some therapeutic maneuvers, like irreverence and humor, were difficult to use cross-culturally. The adaptation and negotiation of interpersonal relationships between clinician, client and interpreter were central to the success of communication. Trust and flexibility were key to the functioning of the triadic relationship. Clinicians, clients and interpreters were found to adopt different roles and responsibilities throughout the session in an ongoing manner. Implications for the training of interpreters and clinicians are debated.