The English Placement Test (EPT) at the University of Illinois at Urbana-Champaign (UIUC) is designed to provide an accurate placement (or exemption) of international students into the ESL writing and pronunciation classes. Over the last five years, UIUC has experienced an increase in the number of international students taking the EPT. Because of the costs of the EPT, various stakeholders have suggested using TOEFL as a substitute placement tool. The purpose of this research is to find out whether TOEFL iBT can serve as a suitable pre-screening tool for placement of international students into the ESL writing courses at UIUC. While there is a general statistically significant tendency that students with higher TOEFL iBT scores are placed into higher levels of ESL classes, there is no particular set of either total or section scores which can be used as a reliable criterion for dividing students into ESL classes without significant misplacement. Furthermore, the correlation between TOEFL iBT and the EPT shows a distinct pattern of time dependence: the correlation is stronger when the time gap between these tests is short but it dramatically decreases and even becomes slightly negative around Week 50; however, starting from the 50th week it increases. Some possible interpretations of the findings as well as recommendations for score users are discussed. (Contains 2 tables and 5 figures.)