Objectives
To propose a Portuguese version of the Objective and Subjective Knowledge and HIV Testing Scale (OSK-HIV-TS), assess its content validity, and perform item analysis after administration to a sample of undergraduate students.

Methods
Three translators translated the OSK-HIV-TS into Portuguese. Judges evaluated each item of a consensus version of the translated instrument for semantic, idiomatic, cultural, and conceptual equivalence. A consensus committee reviewed a back-translation against the original version of the OSK-HIV-TS. Content validity was calculated with the content validity index (CVI) and item analysis was conducted using Classical Test Theory (CTT).

Results
The translated scale achieved semantic, idiomatic, conceptual, and cultural equivalence to the original version. A total of 491 undergraduate students participated and the distribution of students’ responses to the OSK-HIV-TS revealed a high proportion of correct answers. All items were classified as easy or very easy and only item 16 was classified having strong discrimination power according to the discrimination index.

Conclusion
The OSK-HIV-TS is a novel instrument in the Brazilian literature for assessing human immunodeficiency virus (HIV) knowledge and should inspire more research into HIV/acquired immunodeficiency syndrome (AIDS) behavior and associated factors, which, despite being essential and necessary, is still lacking in the Brazilian literature.