This study aims at identifying the effect of two spelling course-teaching methods on the cognitive achievement of third primary grade public education students in the kingdom of Saudi Arabia. The importance of the study lies in the fact that it helps Arabic language teachers to avoid clear deficiencies that prevent students from improving their spelling performance. Added to that, this study can also pave the way to other studies to devise and invent different ways to improve students’ spelling performance. As well, this study tries to shed light on an important aspect of the educational process, which is to figure out the effect of two spelling course-teaching methods on the cognitive achievement of third primary grade public education students in the kingdom of Saudi Arabia. The study used the quasi-experimental method and its sample consisted of 25 students representing the target study sample. The study concluded that the three experiments (experimental spelling course, the new ministerial approach applied for this year (1440/1441 AH), the regular method of developing the written component) have a meaningful effect on spelling course students. Furthermore, there are no significant differences between the effects of these three methods on spelling course students ’achievement. Based on the above results, the educational operators are highly recommended to pay more attention to teaching the students of My Language course book according to the new curriculum. Hence, the educational curricula should include activities and procedures of the main basic spelling skills needed by the primary third grader. In addition, non-specialist teachers should be trained to apply the main basic spelling skills needed by the primary third grader.