Previous studies have examined learner factors such as anxiety, self-efficacy, and achievement motivation in ESL/EFL (English as a second language/English as a foreign language) writing. Studies have affirmed that self-efficacy and achievement motivation could enhance writing performance, whereas anxiety may hinder writing achievement. This study aimed to examine individual differences in Iraqi EFL learners' writing anxiety, writing self-efficacy, and writing achievement motivation in the Iraqi EFL context. A quantitative approach, specifically the correlational design, was employed to examine the above-mentioned relationships. The sample of the study comprised 100 Iraqi undergraduate students majoring in English language from two Iraqi public universities. Data were collected via four instruments: three questionnaires, namely, Second Language Writing Anxiety Inventory (SLWAI), Writer Self-Perception Scale (WSPS) and Achievement Goal Questionnaire (AGQ), and one descriptive writing task. The findings of this study discovered that the higher the writing anxiety level, the poorer the writing performance, whereas the higher the writing self-efficacy and writing achievement motivation level, the better the writing performance. The findings of this study also indicated that both writing self-efficacy and writing anxiety, and writing anxiety and writing achievement motivation were negatively correlated, whereas writing self-efficacy and writing achievement motivation were significantly and positively correlated. This study suggests that these factors need to be taken into consideration in EFL writing instruction to facilitate the teaching and learning process of EFL writing, which in turn would help enhance the EFL undergraduates' writing ability.