The Colorado Learning Attitudes about Science Survey (CLASS) has been widely acknowledged as a useful measure of student cognitive attitudes about science and learning. The initial University of Colorado validation study included only 20% non-Caucasian student populations. In this Brief Report we extend their validation to include a predominately under-represented minority population. We validated the CLASS instrument at Florida International University, a Hispanic-serving institution, by interviewing students in introductory physics classes using a semistructured protocol, examining students’ responses on the CLASS item statements, and comparing them to the items’ intended meaning. We find that in our predominately Hispanic population, 94% of the students’ interview responses indicate that the students interpret the CLASS items correctly, and thus the CLASS is a valid instrument. We also identify one potentially problematic item in the instrument which one third of the students interviewed consistently misinterpreted. © 2009 The American Physical Society.