Abstarct: The study at hand examines the most frequent grammatical mistakes that are made by Iraqi students of English as a foreign language (EFL) during written production. The achievement of grammatical accuracy in writing remains a problem despite years of formal training to many Iraqi students and this is a disadvantage that impacts negatively on the effectiveness and clarity of their writing. The main aim of the study is to find, list down and discuss the common grammatical errors with a view to shedding some light on their origin and some pedagogical remedies. This research uses an applied methodology, involving the gathering of written samples of the EFL learners of the university level in Iraq. The analysis is done both descxriptively and analytically and the errors identified in the data are divided in the category of the common errors: verb tense, subject verb agreement, prepositions, articles, and sentence structure. Patterns that reveal both the effect of the mother tongue and learning gaps of the learners are some of the patterns to be identified by the research by analyzing the frequency and nature of errors. The importance of this research is that it might enlighten the teachers and curriculum developers about the particular challenges faced by the learners and hence lead to more effective pedagogical practices. The results indicate the necessity of the specific remedial programs and stronger focus on grammar in the instruction of writing.