OBJECTIVES: The development of country-specific versions of Spanish-language COA instruments through the linguistic validation process is important to ensure the language used is widely understood by the target audience while maintaining conceptual equivalence to the original instrument. This poster will offer examples illustrating why a universal Spanish version may not be appropriate for all Spanish-speaking populations, while also providing details related to target populations, regional dialects, and instrument types. METHODS: A review of previous linguistic validation projects that included multiple Spanish-speaking countries was conducted. A comparison of different versions, the corresponding linguistic decisions, and details relating to the demographics of the respondent population were analyzed. RESULTS: The review of various COA instruments determined that the Spanish versions often required country-specific adaptation for wide-reaching comprehension, as well as the use of appropriate local medical terminology. Instruments developed for use with adolescents or elderly populations frequently required country-specific adaptation to ensure that the items were fully understood. Other factors included references to education levels, measurements, and idiomatic or colloquial verbiage. CONCLUSIONS: When making decisions regarding language versions, the target population should be taken into consideration. COA instruments are increasingly being developed for adolescent and elderly populations. These audiences may not have the language experience that is conducive to the same understanding of idiomatic or region-specific language that other populations might be more likely to comprehend. In addition, as medical terminology can differ between countries, it is important to develop instruments specific to the targeted country’s population where applicable.