Demographic factors, such as learner background variables, are strongly correlated with aptitude test scores of international English as a Second Language learners. This study conducted a multiple linear regression to assess the role of gender, length of study abroad, and age of international college students enrolled in an English for Academic Purposes program at a Midwestern university in the United States (n=626) in predicting scores on a test of English proficiency. Regression results were significant, although the explanatory power of the overall model was weak. These results suggest that certain learner backgrounds play a role in predicting test performance, and may be of interest language program designers and classroom teachers in placing students, and planning for English as a Second Language courses