The main aim of the current study is to identify the factors that predict Second Language Writing (L2 writing) of Iraqi EFL sophomore students at Departments of English in two colleges: College of Arts and College of Education for Humanities at University of Mosul. To achieve this purpose, data were collected through an online survey with a final sample of 116 students, 35 students from College of Arts and 81 students from College of Education for Humanities. This study used prevalidated adapted scales to collect data, where the motivation scale was based on that of, Khazaee, Dowlataldadi, Amerian, and Fathi (2020), and the transfer scale relied on that in Alsaghier`s study (2020) and Chulak`s study (2023). Simple Linear Regression was utilized to analyze the collected data. The results indicated that motivation and transfer were significant predictors of learners L2 writing performance in both colleges. Gender, however, was not significant in predicting learners L2 writing achievement. The findings of this study have crucial pedagogical implications theoretically and practically. Theoretically speaking, the results of the current study add new information to the existing literature about the predication relationship between multiple factors like the ones in this study with EFL students performance in writing. In terms of practical insights, this study is hoped to enlighten instructors about the importance of motivation and transfer in learning writing, the most difficult skill among the four skills, reading, writing, spelling, and listening, writing is the most difficult skill. especially for EFL learners.