Previous studies have highlighted the unique challenges that may threaten the well-being of teachers in CLIL/ EMI contexts, as well as unique opportunities that may positively impact their well-being (Moate, 2011; Pappa et al., 2017; Talbot et al., 2021). Results from Talbot et al. (2021) suggest that, in the Austrian context, the well-being of secondary CLIL teachers may be more at risk than that of tertiary EMI teachers. As such, the present study aimed to investigate this notion further through a comparative survey examining the well-being and job satisfaction of secondary CLIL and tertiary EMI teachers in Austria. In total, 123 secondary CLIL teachers and 219 tertiary EMI teachers completed the questionnaire survey. Results show that CLIL teachers tended to score consistently lower on several key dimensions related to well-being than EMI teachers, while the differences in job satisfaction were far less pronounced. Thus, the findings of this study lend empirical support to the notion that CLIL teachers at Austrian secondary schools may be more at risk in terms of their well-being than their colleagues at tertiary level. The survey data also provides valuable insights into teacher beliefs associated with professional well-being. An important implication for practice is that those teachers who felt more adequately trained to teach CLIL/EMI classes tended to report significantly higher professional well-being than their colleagues at both the secondary and tertiary level.