STUDY DESIGN: Clinical measurement. OBJECTIVES: To translate, adapt, and test the measurement properties of the Brazilian Portuguese version of the Victorian Institute of Sport Assessment-Patella (VISA-P) questionnaire. BACKGROUND: It is important to objectively measure symptoms and functional limitations related to patellar tendinopathy using outcome measures that have been validated in the language of the target population. Cross-cultural adaptations are also useful to enhance the understanding of the measurement properties of an assessment tool, regardless of the target language. METHODS: The VISA-P questionnaire was translated into Brazilian Portuguese, culturally adapted, and titled VISA-P Brazil. It was then administered on 2 occasions with a 24- to 48-hour interval between them, and a third time after a month of physical therapy treatment. The following measurement properties were analyzed: internal consistency, test-retest reliability, agreement, construct validity, floor and ceiling effects, and responsiveness. RESULTS: The VISA-P Brazil had high internal consistency (Cronbach α = .76; if item deleted, Cronbach α = .69-.78), excellent reliability and agreement (intraclass correlation coefficient = 0.91; 95% confidence interval: 0.85, 0.95; standard error of measurement, 5.2 points; minimal detectable change at the 90% confidence level, 12.2 points), and good construct validity (Pearson r = 0.60 compared to Lysholm). No ceiling and floor effects were detected for the VISA-P Brazil, and the responsiveness, based on 32 patients receiving physical therapy intervention for 1 month, demonstrated a large effect size of 0.97 (95% confidence interval: 0.68, 1.25). CONCLUSION: The VISA-P Brazil is a reproducible and responsive tool and can be used in clinical practice and research to assess the severity of pain and disability of patients with patellar tendinopathy.