A study compared four tests of English as a Second Language (ESL) used for placement of students of varying language backgrounds and skill levels in an intensive ESL program. The tests were a text-based listening and reading test, a listening dictation, a self-assessment questionnaire, and a self-reported vocabulary size test. All measures were administered to 93 candidates on entry into the program. Results indicate that the instruments performed differentially overall, by proficiency level, and by native language background. In general, the first two tests, which required demonstration of proficiency and were text-based, worked best. Neither self-report measure worked well, although the questionnaire worked better than the vocabulary test. Possible explanations for these findings are seen in test design, content, and tasks required. (MSE)