Gamification is implemented commonly in educational contexts in order to support teaching and learning processes. To gamify learning is to add game elements to an activity, including assessment, and use it for educational purposes. However, its effects as a tool for assessment still requires more exploration. This study aimed to examine the effects of gamified e-quizzes on the Omani grade seven students' learning achievement and engagement. The study adopted quasi-experimental method research design. It was conducted on a sample of 58 female students from Hind Bint AlMuhallab Basic Education School for (Grade 5-10) located in Sohar city. The study sample was divided into two groups: control (30 students) and experimental (28 students). The control group was the non-gamified group, while the experimental group was the gamified one. The experimental group was assessed based on the impact of gamified e-quizzes on the students' learning achievement and engagement in the Information Technology subject (IT) in a period of time during the first semester of the academic year 2021-2022. The gamified e-quizzes were designed by the researcher using Kahoot and Quizizz mobile applications. To collect data, pre and post tests were implemented and then scores between the experimental and control groups were compared. In addition, a questionnaire was distributed among the experimental group after the experiment intervention as an instrument to measure the effects of gamified e-quizzes on the students' engagement in learning the IT subject. The results indicated that there was a statistically significant difference between the two groups in the students' achievement in favour of the experimental group in which the students who used the gamified e-quizzes for formative assessment got better scores in the achievement test compared to the control group students who took the paper-based quizzes. The gamified e-quizzes as a formative assessment tool also had positive effects on students' engagement in learning the IT subject. The researcher recommended using gamified e-quizzes by teachers as an effective formative assessment tool to promote students' achievement and engagement in learning.