Given the cost and difficulty of running medical education programs instructed in a second language, the selection of students who are likely to perform well becomes an important consideration. Previous studies have focused on different predictors such as aptitude, personality and English language proficiency. The purpose of the present study was to examine the potential offered by technical vocabulary recognition levels of the students as predictors of their success. To this end, a frequency based corpus of 162 technical words was established from their textbook. Taking Nation’s Levels Test as a model, a receptive technical vocabulary test was constructed and administered to 88 students at the end of the semester. The scores were correlated with the grades they were awarded in pharmacology. The findings of the study reveal that the students’ technical vocabulary test results correlated significantly with their grades.