BACKGROUND:The ability to understand instructions on drug bottles, appointment slips and medical education brochures could be affected by patients' health literacy. Healthcare providers need to be aware of, hence, assess patients' literacy before they develop effective educational strategies for these patients. Many validated instruments have been used to evaluate literacy of diabetic patients in the English language, only a limited number is available in Arabic. OBJECTIVE:To translate and culturally-adapt the Simplified Diabetes Knowledge Test (DKT), the Literacy Assessment for Diabetes (LAD), and the Diabetes Numeracy Test (DNT) for potential use in Arabic-speaking countries. METHODS:A formal process based on the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) guidelines was adopted in translating and culturally adapting the three tools. An expert panel reviewed forward and backward translations of the tools. Ten diabetic patients participated in the cognitive debriefing process to evaluate the tools for clarity, simplicity, and comprehensiveness, and to assess their cultural equivalence. RESULTS:Only minor changes were introduced in tools' design, appearance, and instructions. However, issues identified during the expert panel review and cognitive debriefing led to modifying the tools resulting in item re-wording, addition, deletion or re-arrangement. Terms such as glycosylated hemoglobin, carbohydrates, and infection were adapted to cumulative sugar, starch and microbial inflammation respectively. Issues related to cultural and conceptual equivalence were resolved by replacing words such as kilo instead of pound, and supper instead of dinner, or adding diacritics to the Arabic word for "kidney". The original 43 items of the DNT were reduced to 26, eliminating questions with the same mathematical calculations within each tool domain. CONCLUSIONS:A Culturally equivalent version of the Simplified DKT, LAD and DNT have been developed in the Arabic language available to be used in research and clinical practice in the Arabic speaking countries.