Background: The current cognitive tests have been developed based on and standardized against Western constructs and normative data. With older people of minority ethnic background increasing across Western countries, there is a need for cognitive screening tests to address factors which influence performance bias and timely diagnostic dementia accuracy. The diagnostic accuracy in translated and culturally adapted cognitive screening tests and their impact on test performance in diverse populations have not been well addressed to date. Objective: This review aims to highlight considerations relating to the adaptation processes, language, cultural influences, impact of immigration, and level of education to assess for dementia in non-Western and/or non-English speaking populations. Methods: We conducted a systematic search for studies addressing the effects of translation and cultural adaptations of cognitive screening tests (developed in a Western context) upon their diagnostic accuracy and test performance across diverse populations. Four electronic databases and manual searches were conducted, using a predefined search strategy. A narrative synthesis of findings was conducted. Results: Search strategy yielded 2,890 articles, and seventeen studies (4,463 participants) met the inclusion criteria. There was variability in the sensitivity and specificity of cognitive tests, irrespective of whether they were translated only, culturally adapted only, or both. Cognitive test performance was affected by education, linguistic ability, and aspects of acculturation. Conclusions: We highlight the importance of translating and culturally adapting tests that have been developed in the Western context. However, these findings should be interpreted with caution as results varied due to the broad selection of included cognitive tests.