• Cross-Cultural Exploration: The study delves into the perceptions of critical thinking skills among Malaysian and Vietnamese undergraduate students, offering a unique cross-cultural perspective. • Diverse Participants: In-depth interviews were conducted with 16 participants, including first-year and final-year undergraduates, presenting a wide spectrum of high-order thinking skills. • Phenomenographic Approach: Employing the phenomenographic approach, the research uncovers three fundamental conceptions of critical thinking skills, nested within three overarching domains: cognitive, dispositional, and spoken discourse. • Cognitive Dimensions: Within the cognitive domain, the study reveals two distinct approaches: the idealistic and the realistic. These approaches emphasize the theoretical and practical dimensions of critical thinking, offering insights into students' ability to analyze complex concepts and solve intricate problems. • Dispositional Insights: The dispositional domain uncovers the dichotomy of collectivist and individualist perspectives. It highlights how students approach critical thinking within group dynamics and as independent thinkers, shedding light on their motivations and attitudes. • Spoken Discourse: In the spoken discourse domain, two distinct approaches emerge: the product-oriented and the process-oriented. These approaches emphasize the tangible outcomes and cognitive processes of critical thinking, respectively. • Tailoring Pedagogy: The study's findings underscore the importance of customizing pedagogical instruction to accommodate the diverse perspectives and methodologies employed by students in their approach to critical thinking skills. Educators are encouraged to adapt their teaching strategies to align with students' multifaceted modes of critical thinking across various academic levels. 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. [ABSTRACT FROM AUTHOR]