The present study contributes to developing a Public Speaking Class Anxiety Scale (PSCAS) to measure anxiety in the EFL public speaking class in the Thai context. Items were adopted from previous scales: Foreign Language Classroom Anxiety Scale (FLCAS) by Horwitz et al. (1986); Personal Report of Communication Apprehension (PRCA-24) and Personal Report of Public Speaking Anxiety (PRPSA-34) by McCroskey (1970); and Speaker Anxiety Scale (SA) by Clevenger and Halvorson (1992) based on their critical appraisals. Some minor changes in wordings of adopted items were made to a preliminary PSCAS and were validated. The preliminary PSCAS yielded an internal consistency of 0.84 using Cronbach's alpha coefficient when administered to 76 participants and was factor-analyzed to establish the construct and the final version. The factor analysis revealed that the PSCAS included the components of communication apprehension, test anxiety, fear of negative evaluation, and comfort in using English in a public speaking class.