The purpose of this action research was to investigate the use of YouTube videos and interactive activities in stimulating critical thinking among students from a public university in Malaysia. There were 50 students of mixed background, comprised of local and foreign students who participated in this study which lasted for one semester. Data was collected using a few approaches which included video recording of the lessons, students' and researcher's reflections and role play. In this paper, we specifically focus on the students' reflections of their experience while using YouTube videos. Thematic analysis was conducted to examine the themes that emerged in their reflections. Using Lewin's Action research model supported by Constructivism Theory, a-four stage action research consisted of planning, acting, observing and reflecting were conducted. We found that YouTube Videos were fun and interesting, increased students' participation and engagement and enhanced their critical thinking skills. The students were able to participate actively and demonstrated strong interest in the learning process as they were able to understand lectures better by visualizing the content and relating it to real workplace. Our study revealed the potential of YouTube video as a tool for stimulating students' learning and enhancing their critical thinking.