BACKGROUND: Depression is a common condition in primary care medicine in all population groups. We wanted to validate an Arabic translation Zung Self-Rating Depression Scale for Arabic speakers as it has been validated in a number of other languages. METHODS: The hospital translation service translated the English version into Arabic, which was verified by back translation. This version was tested in a pilot study with 40 bilingual Arabic-English clinicians and Arabic linguistic experts. Revised questions were subjected to another translation-back translation and the final version tested in a clinical trial with 240 consenting bilingual English-Arabic speakers. The subjects were randomly assigned to answer either the English or Arabic version of the Zung questionnaire first, ensuring that subjects had no access to previous answers when answering the questionnaire in the other language. The scores obtained were tested for agreement using the kappa statistic. RESULTS: We found substantial agreement between the scores obtained from the two questionnaires. The kappa measurement of agreement was 0.652 (95% confidence interval, 0.571-0.732) CONCLUSION: We believe the Arabic translation of the English Zung Self-Rating Depression Scale is valid and reliable, and will be useful to practitioners who would like to use this tool in Arabic-speaking patients. Publication Types: Clinical Trial Randomized Controlled Trial Validation Studies