This study assesses the level of application of the 5E’s educational model by Rwandan physics teachers and how the model affects the learning of basic classical mechanics in secondary school physics classrooms. For this analysis, quantitative data were collected using the classroom observation tool framed at the 5E’s educational model. A sample of six secondary physics teachers was selected purposively from three boarding secondary schools of Nyamasheke district in the western province of Rwanda to participate in this study. Twenty-four classroom observations were conducted during teaching and learning mechanics concepts in the way of four observations for each teacher before being trained on 5E’s educational model. This was done to help the researcher to have the real picture of the prior ability of teachers to incorporate 5E’s aspects in their usual teaching practices. Similarly, a total of 24 observations were done after teachers’ training. The collected data were tabulated in Microsoft Excel, and descriptive statistics were analyzed and presented. The overall mean scores on the teachers’ ability to apply 5E’s educational model during lesson delivery on introductory mechanics were low before training and increased due to teacher training on the use of 5E’s educational model. The main findings from this study revealed that 5E’s educational model is more effective in stimulating students’ motivation and strong interaction and a better understanding of mechanics concepts through interactive activities, discrepant events, and computer simulations. Based on the findings of this study, some recommendations were suggested that would improve more physics students’ active learning. Keywords: active learning of mechanics, 5E's educational model, classroom observation, physics students, secondary school, Rwanda