The purpose of this study was to investigate to what extent Korean college students can acquire vocabulary from reading course materials. The participants were 32 college students who enrolled in a TEFL methodology course. A vocabulary test was administered at the beginning and the end of the course, and the results showed that the participants were able to recognize meanings of an average of 3.6 new words, suggesting that small but significant amounts of incidental vocabulary learning can occur as a result of reading course materials. The findings also showed that there was a statistically significant relationship between the number of times each word occurred and its relative learning gain. The results of this study suggests that incidental vocabulary learning is possible from reading even though the amount of such learning is not large. Implications for vocabulary learning and teaching are discussed.