Previous research has demonstrated that without the use of professional interpreters, language barriers interfere with patient care. The literature recommends documenting the presence of language barriers in medical charts. To our knowledge, this mixed methods study is the first to examine language documentation practices in a Canadian inpatient psychiatry setting. The research team interviewed 122 patients admitted to a tertiary care psychiatry ward in Montreal, Canada between 2016−2017 to assess their ability to communicate in the healthcare establishment's languages (English/French). Nineteen participants identified as having a language barrier were selected for a qualitative analysis of the retrospective audit of their medical charts. The presence of a language barrier was reflected in 68% of these charts. When a language barrier was documented, professional interpreters were never used. Our qualitative analysis, informed by literature on medical discourse, aimed to provide clinical, administrative, and organizational recommendations to optimize the utilization of interpreting services in psychiatric wards. Documentation of language data was inconsistently collected, often vague, and shed light on the clinical challenges involved in differentiating language barriers from psychopathology. Normalization of limited care for language diverse patients was reflected in the clinical notes. Findings show that a change of organizational culture is imperative to provide optimal care to language diverse patients. We recommend clinician education and standardization of documentation practices, along with institutional policies supporting the systematic use of professional interpreters in mental healthcare settings, to maximize human rights and patient safety, and to bring medical practices to an acceptable standard of care.