Background and purpose: Assessment of digital health literacy should be a major concern for healthcare providers. We aimed to translate and adapt the Digital Health Literacy (DHL) Instrument into Brazilian Portuguese and examine the content validity for individuals with heart failure (HF). Methods: The instrument was translated, back translated, and evaluated by a panel of six experts regarding linguistic equivalences. An agreement analysis was performed, with values ≥80% considered acceptable. The experts then evaluated clarity, theoretical relevance, and practical pertinence. The content validity index (CVI) was calculated for each item. A CVI ≥.83 was considered acceptable. The expert's opinions were also evaluated through the modified kappa coefficient for content validity studies. Values >.74 were considered excellent. The content validity ratio (CVR) was also calculated. A critical value of CVR of 1.00 was determined. Cognitive testing (understanding the meaning of each item and their respective answers) was performed with 33 individuals with HF. Results: The adapted version obtained an agreement of ≥83.3% for each item on linguistic equivalences. Total CVI was ≥0.83, kappa values for each item were >.74, and the CVR values were 1.00 for all items. After two rounds of evaluation, all patients were able to understand the items and response scale. Conclusions: The Brazilian version has satisfactory evidence of linguistic and content validity to measure DHL in patients with HF. Additional psychometric properties will be tested in the country.