Handwriting is an essential and indispensable skill in learning a language. Its importance lies in its being the product upon which the EFL learners' linguistic performance can be judged and evaluated. Students' poor handwriting negatively affects their overall academic achievement. This study investigates the knock-on effects of students' poor handwriting on their performance in the assessment methods of academic courses. It also aims to know teachers' impressions and perceptions about their students' poor handwriting and its relation to their low academic performance. In this study, (N=64) EFL learners (male and female) from levels 2,3,7, and 8 studying the courses (Grammar 2, Writing 3, Research Methodology, and Preparation for International Tests) at King Khalid University, were selected and dictated a text for writing on specific papers designed for writing the English letters and words. The researchers use Smith JC's (2010) six criteria to evaluate learners' handwriting. The results substantiate that those learners whose handwriting is unsatisfactory scored low marks whereas those with good handwriting scored high marks in exams. Based on the findings, the study concludes with recommendations on how students can improve their handwriting to score satisfactory marks in all courses.