This research endeavors to delve into the nuanced perceptions of critical thinking skills held by undergraduate students in Malaysia and Vietnam. The study employs a robust research methodology, involving in-depth interviews with a cohort of 16 participants, drawn from both first-year and final-year undergraduates. Through the rigorous application of the phenomenographic approach, the investigation uncovers three fundamental conceptions of critical thinking skills, categorized within three overarching domains: cognitive, dispositional, and spoken discourse. Within the cognitive domain, two distinctive approaches surface: the idealistic and the realistic. The idealistic perspective underscores the theoretical and aspirational dimensions of critical thinking, spotlighting students' capacity to dissect intricate concepts, establish interconnections between seemingly disparate ideas, and generate innovative solutions to multifaceted problems. Conversely, the realistic approach recognizes the evolution of critical thinking skills over time, emphasizing deliberate practice and reflection on real-world challenges and experiences. The dispositional domain illuminates the dichotomy between collectivist and individualist perspectives, unveiling the diverse manners in which students engage with critical thinking within the framework of group dynamics or as autonomous thinkers. In the spoken discourse domain, two discernible approaches emerge: the product-oriented and the process-oriented. The product-oriented stance accentuates tangible outcomes of critical thinking, such as persuasive arguments, articulate and coherent written expression, and adept problem-solving. In contrast, the process-oriented approach underscores the intricate cognitive and metacognitive processes intrinsic to critical thinking, encompassing activities like information analysis, evaluation, idea integration, and the cultivation of innovative insights. This study's findings underscore the necessity of customizing pedagogical instruction to harmonize with the diverse perspectives and methodologies embraced by students in their approach to critical thinking skills. © 2023 Elsevier Ltd