Background: Technological advancements had given rise to novel approaches in nursing education; one of these approaches is Kahoot!. This game-based platform offers a dynamic alternative to traditional assessments, fostering a dynamic and enjoyable learning environment. Aim: This study aims to determine the effect of using Kahoot! as a digital game-based formative assessment tool on nursing students' knowledge and learning motivation. Setting: Faculty of Nursing, Alexandria University, Egypt. Research design: A quasi-experimental research design. Subjects: A sample of 150 nursing students who were selected through a simple random sampling process. They were divided into two groups, each group consisting of 75 students. Tools: Three tools were used for data collection: “Nursing Students' Knowledge Test (NSKT)", “Nursing Students' Learning Motivation Questionnaire (NSLMQ)" and “Kahoot! Game-Based Learning Feedback Questionnaire (KGBLFQ)". Results: After applying Kahoot!, 93.3% among the study group significantly achieved satisfactory level of knowledge and 94.7% showed a high level of learning motivation compared to only 33.3% and 68.0% respectively among the control group. These differences between the study and control groups after applying Kahoot! were statistically significant as (p₂<0.001). Positive feedback about Kahoot! as a digital game-based formative assessment tool was given by 94.7% among the study group. Conclusion: Kahoot! as a digital game is a valuable formative assessment tool. It is significantly enhancing students' knowledge regarding the educational objectives and learning motivation. Recommendations: Nursing educators should link Kahoot! as a formative assessment tool to specific learning outcomes to enhance students' knowledge and motivation. Further research is needed to explore the long-term effect of Kahoot! on sustained retention of knowledge and learning motivation.