This current study aims at investigating the impact of using inductive and deductive teaching upon EFL undergraduate students' achievement at the Hashemite University. More specifically, the study attempts to explore the effect of using inductive and deductive approach on students' achievement in some grammatical issues included a book adopted for teaching Grammar 2 in the Department of English Language and Literature. The research instrument used is a pre-post-test developed by the researchers. Two groups of students are chosen for the purpose of the study. Whereas the experimental group was taught through inductive approach, the controlled group was taught through the deductive approach. Results show significant differences between the means of students' scores in the two groups on the post-test, in favor of the experimental group. Results also reveal no significant differences according to study-year, the type of school they graduated from, and gender. In light of these results, the researchers suggest some recommendations for TEFL researchers and EFL instructors.