OBJECTIVES: There are no measures of health-related absenteeism and presenteeism validated for use in the large and increasing US Spanish-speaking population. The first steps in adapting an English language questionnaire for use in this population involve a reiterative process of creating harmonized forward and back translations by independent translators and cognitive debriefing of subjects following questionnaire administration. This process (linguistic validation) establishes the conceptual equivalence of the translation to the original and the cultural appropriateness of the translation. METHODS: To evaluate the linguistic validity of the US Spanish version of the Work Productivity and Activity Impairment questionnaire, General Health Version (WPAI:GH), a bilingual (Spanish-English) interviewer debriefed subjects after self-administration of the US Spanish (N=31) and English (N=35) WPAI:GH. Subjects were stratified equally by educational level, with and without a high school degree. RESULTS: The item comprehension rate was 98.6% for Spanish and 99.6% for English. Response revision rates during debriefing were 1.6% for Spanish and 0.5% for English. Responses to hypothetical scenarios indicate that both language versions adequately differentiate sick time taken for health and non-health reasons and between absenteeism and presenteeism. CONCLUSION: Linguistic validity of the US Spanish translation of the WPAI:GH was established among a diverse US Spanish-speaking population, including those with minimal education.