Inasmuch as the fact that writing is a cognitively demanding task and as a step toward overcoming some of the barriers English as a Foreign Language (EFL) learners face during writing performance, this study attempted to investigate Iranian EFL learners' perceptions toward the most common writing difficulties. To this end, 120 Iranian EFL learners from Golestan University, Iran, filled out a reliable and validated questionnaire. The results of the questionnaire and the semi-structured interviews (N = 24) revealed that most of the participants agreed that for teaching grammar and punctuation, they should be embedded in a context and be integrated with the four skills. They also believed that teachers should use punctuation appropriately in their writings themselves and teach them to students explicitly. Besides, it was believed that through using mnemonics, students can better learn words spelling. The results of the interviews revealed grammar, spelling, punctuation, choice of words, organization, and familiarity with genres and rhetorical structures, negative transfer from Persian to English, and idiomatic expressions and collocations are the other factors that make the writing task difficult. Based on the students' perceptions, the findings of this study can inform English language teachers to teach grammar, punctuation, and spelling by contextualizing them in an appropriate context, and they offer some practical implications for teachers, learners, material developers, and curriculum designers in this regard.