This study aims to examine levels of speaking anxiety and the contributing factors among EFL learners through the Foreign Language Classroom Anxiety Scale (FLCAS) proposed by Horwitz (1986) in a vocational high school (SMK) classroom in Sukoharjo, Central Java, Indonesia. A qualitative case study with addition quantitative descriptive data were employed in this research. By conducting a set of FLCAS questionnaires to 31 students and seven interviews, as representatives of each speaking anxiety level. A descriptive quantitative analysis was conducted to obtain supporting data, and the interview data were analyzed using an interactive model by Miles and Huberman (2014). The findings reveal that 19 of 31 students in the classroom experienced a moderate level of speaking anxiety. Seven students also acknowledged that their speaking anxiety intensified through several factors: psychological, environmental, linguistic, social, and familial. These findings suggest that speaking anxiety is a condition that can be found at any educational level, even in vocational high school, where the students are required to be fluent in oral communication for workplace needs.