The COVID-19 pandemic transformed a traditional classroom setting into an online classroom setting, including the teaching and learning process in the English for Specific Purposes (ESP) context. The change influenced the students' motivational state. This study aimed to investigate the students' perception of the demotivating teaching strategies in ESP online learning classes during the COVID-19 pandemic. One hundred and sixty-five students of the Faculty of Vocational Studies in an Indonesian public university participated in the study. They completed a questionnaire that reflected their perception of the least and most motivating teaching strategies. Their perception was rank-ordered to find the teaching strategies that were demotivating. The results showed that the students did not feel motivated when the teachers mentioned that mistakes were a natural part of learning. They also perceived giving challenging tasks, creating group work, inserting personal content into assignments, and offering a variety of material as demotivating practices in ESP online classes. The results are expected to provide a solution and modeling to improve students' motivational state through motivating teaching strategies in ESP classes, especially in a vocational education setting. Further research should elaborate and expand the studies using more variables since students' motivation is influenced by many factors.