The Acoustic Voice Quality Index (AVQI) is a relatively new clinical method to quantify dysphonia severity. Since it partially relies on continuous speech, its performance may vary with voice-related phonetic differences and thus across languages. The present investigation therefore assessed the AVQI's performance in English, Dutch, German, and French. Fifty subjects were recorded reading sentences in the four languages, as well as producing a sustained vowel. These recordings were later edited to calculate the AVQI. The samples were also perceptually rated on overall dysphonia severity by three experienced voice clinicians. The AVQI's cross-linguistic concurrent validity and diagnostic precision were assessed. The results support earlier data, and confirm good cross-linguistic validity and diagnostic accuracy. Although no statistical differences were observed between languages, the AVQI performed better in English and German and less well in French. These results validate the AVQI as a potentially robust and objective dysphonia severity measure across languages.