While previous research on student success has focused on disciplinary academic classes and programs with varying results regarding the predictive validity of English proficiency tests, namely the International English Language Testing System (IELTS), none have studied student success within the non-program-specific context of an English for academic purposes (EAP) program in which the cut scores set by the university align with the IELTS guidance. Using data collected during the intake of new international students and at the completion of each semester, this study primarily sought to determine how students placed via IELTS fared compared to those placed via other tests, including the in-house English placement test (EPT), and whether they were more likely to fail EAP courses during their first semester. Across six semesters, success data for 663 English language learners (ELLs) enrolled in EAP courses during their first semester at the university were collected and compared on the basis of the placement test used, students' test scores, and their final course grades. Logistic regression analysis results revealed that the EPT performed significantly better in placing students into level-appropriate courses than IELTS. The findings indicate the predictive value of the in-house EPT process and suggest further research into semester-to-semester variations, emergent placement methods, and the probability of seeking services to mitigate academic challenges.