Results from the Ontario Secondary School Literacy Test (OSSLT) indicate that English as a Second Language (ESL) and English Literacy Development (ELD) students have comparatively low success and high deferral rates. This study examined the 2002 and 2003 OSSLT test performances of ESL/ELD and non-ESL/ELD students in order to identify and understand the factors that may help explain why ESL/ELD students failed the test at relatively high rates. The analyses also attempted to determine if there were significant and systematic differences in ESL/ELD students' test performance. The performance of ESL/ELD students was consistently and similarly lower across item formats, reading text types, skills and strategies, and the four writing tasks. Using discriminant analyses, it was found that "narrative" text type, "indirect understanding" skill, "vocabulary" strategy of reading, and the "news report" writing task were significant predictors of ESL/ELD membership. The results of this study provide direction for further research and instruction regarding English literacy achievement for these second language students within the context of having to complete large-scale English literacy tests designed and constructed for first English language students. (Contains 3 tables and 5 footnotes.)