Given the cost of running second or foreign language teacher training programs with a high number of in-school placement hours, the selection of candidates who are likely perform well academically and complete their studies is an important consideration. The purpose of the present study was to examine the potential offered by vocabulary profiles as predictors of academic performance in undergraduate Teaching English as a Second Language (TESL) programs. To this end, vocabulary profiles were established for 122 TESL students by means of an analysis of 300-word samples of their writing. The students' scores on each profile component were then correlated with the grades they were awarded in two of the grammar courses in their program of study. Finally, the effect of the students' mother tongue on both their vocabulary profiles and academic results was considered. The findings of the study reveal that the students' vocabulary profile results correlated significantly with grades in the more procedurally oriented of the two courses. Furthermore, vocabulary profiles proved to be useful in carrying out a finer assessment of the language skills of high proficiency nonnative speakers than oral interviews can offer. (Contains 5 tables.)