PurposeSpeech-language pathologists report bilingual aphasia as the most challenging condition to assess and treat in neurorehabilitation settings, particularly because of limited access to standardized language assessments. This systematic review seeks to identify standardized assessments used by researchers to document premorbid language history and postmorbid language abilities in Spanish-English speaking bilingual persons with aphasia (SE BPWA), quality of psychometric properties of these language assessments, and the extent to which researchers use psychometric data to interpret scores from these assessments.MethodsA systematic search of PubMed, PsycINFO, Web of Science, and CINAHL databases was conducted in August 2023 for studies that met inclusion criteria (primary data of bilingual Spanish-English speaking adult participants with acute onset aphasia). Data pertaining to language assessments was synthesized in proportions and the identified language assessments were evaluated for psychometric robustness by examining published norms and/or test manuals. Risk of bias was assessed for each of the included studies and the overall certainty of the systematic review was assessed.ResultsTwenty-eight studies describing 262 (non-unique) SE BPWA were included in the systematic review. Information on how aphasia was diagnosed (8/28) and its characterization (17/28) was inconsistently reported. Across studies, premorbid language background was most frequently documented using the Language Use Questionnaire (17/28). Postmorbid language abilities were most commonly assessed using the Bilingual Aphasia Test (BAT, English N =19, Spanish N = 20), although using different versions (for Spanish) and not in its entirety. None of the assessments met all nine COSMIN categories for psychometric quality assessment. Three assessments have (limited) bilingual SE normative data: BAT-short version, Boston Naming Test, and Object and Action Naming Battery. However, no study referenced these norms or other SE norms. Critical appraisal ratings were Low for all the studies, impacting the certainty assessment of the current systematic review.ConclusionsThe limited psychometric quality of currently used language assessments poses increased risk of misdiagnoses for SE BPWA, furthering health disparities. This, coupled with the high risk of bias in individual studies, substantially reduces the generalizability and transparency of existing empirical research for advancing scientific understanding of bilingual aphasia. Researchers and clinicians are recommended to utilize available norms and better document participants’ aphasia characteristics.