The relationship between language learners' L1 and L2 writing productions has attracted the attention of researchers since Kaplan (1966). Along this research line, the present study aimed to explore the reverse transfer of rhetorical patterns from English (L2) to Persian (L1) in the argumentative essays of EFL students in Iran. Sixty MA university students (30 English-majors and 30 non-English-majors) participated in the study. Adopting the scheme developed by Kubota (1998a, 1998b), the study focused on the organization of the essays. The main findings of the study are (a) the non-significant difference between L1 and L2 essays of the same student in both English and non-English majors (b) the positive and significant correlation between the qualities of L1 and L2 essays in both English and non-English majors, (c) and the probable transfer of English-specific organization patterns from L2 to L1 especially among English majors.