In this study, the authors evaluated the strengths and limitations of a self-assessment based on ACTFL Can-Do statements ("ACTFL," 2013]) as a tool for measuring linguistic gains over an internship abroad in Russia. They assessed its reliability, determined how its items mapped with the ACTFL scale, and measured the degree to which students' self-evaluations matched oral proficiency interview (OPI) test results (i.e., predictive validity). Data revealed a high level of reliability. Furthermore, self-assessment items ascended in the order of difficulty expected (i.e., Superior items were the most difficult, followed by Advanced), but differences between the means for items representing the ACTFL levels were not statistically significant. Finally, while students demonstrated significant gains from pre- to posttests on both the OPI and the self-assessment, correlations between these measures were only moderate.