This study aims to explore English as a Foreign Language (EFL) students’ understanding and perceptions of applying critical thinking to their practice of speaking skills. Although some research papers have been implemented to understand the impact of critical thinking on learners’ language skills, the study specifically investigates how critical thinking can affect speaking ability amongst learners of low-English levels who are from a non-English-speaking country, according to their perceptions. The participants are 190 undergraduate students whose English proficiency was pre-intermediate and who were enrolled in English for IELTS preparation programs at the Creative Language Center (CLC) of Ton Duc Thang University, Vietnam. A survey was sent to collect information about students’ learning experiences and opinions on their performance of speaking skills integrated with critical thinking. The findings highlighted some challenges when students used critical thinking while practicing oral communication skills, including their habits of learning and insufficient opportunities to practice the skills. Also, students’ awareness of the important role of critical thinking in improving their speaking performance and confidence was successfully noted.