Objective, To produce Spanish versions of common arthritis outcome measures: the Health Assessment Questionnaire (HAQ) Disability Scale, the Center for Epidemiologic Studies Depression Scale (CES-D), the Medical Outcomes Study (MOS) Pain Severity Scale, the Arthritis Self-Efficacy Scale for Pain and Other Symptoms (with the addition of 2 new items), the Visual Analogue Pain Scale, the MOS Self-Rated Health Item, and a Physical Activities Scale that would be usable by most Hispanics living in the US, We tested these translated measures for reliability and, where appropriate, validity, Methods, Instruments were translated and back translated by bilingual persons from 5 different countries of origin, Translators met to resolve variations in translation, The instruments were then administered to Hispanic arthritis patients in 6 geographic locations (5 in the United States and 1 in Latin America), All instruments underwent standard psychometric testing, As appropriate, the sample was stratified by level of acculturation, nation of origin, and geographic location, Results, The translated instruments, with slight modification, met acceptable levels of reliability and validity, They are understood and easily usable by diverse Spanish-speaking populations, Conclusion, The availability of these translated outcome measures should enable investigators to include monolingual Spanish-speakers into their studies, and should facilitate study of cross-cultural differences with respect to these specific outcomes.