<p>For Arabic-English bilingual students, writing is a particularly challenging task, as it requires learning how to produce meaning through written scripts, distinctively different from those of the mother tongue. In this study, subjective familiarity ratings and vocabulary knowledge scores of the printed words of the Peabody Picture Vocabulary Test (PPVT) were collected from native Arabic speakers whose English proficiency was at least at the competent-user level (as per International English Language Testing System [IELTS] criteria). This level of competency is generally the precondition for admission of second-language learners to English-medium universities. The aim of the study was two-fold: (a) to determine the information upon which participants’ vocabulary knowledge relies through an examination of the extent to which such knowledge is predicted by key subjective and objective word properties; and (b) to assess the degree to which participants’ vocabulary knowledge, estimated from printed word comprehension (WC), is related to second-language students’ writing performance, as well as writing anxiety. In this study, objective word properties (e.g., frequency counts and the number of semantic neighbors), as well as subjective familiarity ratings of printed words, notably contributed to vocabulary knowledge (as indexed by WC scores). Furthermore, participants’ vocabulary knowledge was related to writing performance, as well as writing anxiety. Thus, the printed words of the PPVT could be used to predict not only the vocabulary knowledge of Arabic-English speakers admitted to university-level courses but also writing difficulties, thereby informing selective preemptive interventions.</p>