The purpose of the present study was to explore Taiwanese EFL university learners’ strategy use preferences, and to examine the joint effects of anxiety, motivation, extroversion, and English achievement on language strategy use. A total of 118 (57 males, 61 females) EFL university freshmen taking General English II satisfactorily completed the Foreign Language Classroom Anxiety Scale, the Motivation Questionnaire, the Guilford Personality Inventory, and the Strategy Inventory for Language Learning. Participants’ English achievement was measured by means of their semester results (midterm and final examinations). The results showed that cognitive and compensation were the most frequently used strategy categories, followed by metacognitive and affective, while memory and social were the least frequently used strategy categories. In general, foreign language anxiety was negatively correlated with most of the strategy categories, while motivation, extroversion, and English achievement were positively correlated with most of the strategy categories. Motivation was the best predictor of overall strategy use, and English achievement was the next best predictor, followed by extroversion. Together, these three factors were able to explain 33.6% of the variance in overall strategy use. In addition, motivation, extroversion, and English achievement mediated the relationship between anxiety and overall strategy use. It is concluded that high motivation, high extroversion, high English achievement, and low foreign language anxiety should be emphasized simultaneously for enhancing EFL learners’ language strategy use.