This study examines the impact of reading on vocabulary development with adult ESL students at the National Institute of Technology (Trichirappalli, India). The researcher analyzes the performance of the students who devoted their time to reading, and the students who learned consciously the meaning of words to develop their vocabulary knowledge. The results of the pre- and posttest confirm that readers were able to use the subconsciously acquired words in sentences, whereas the subjects who spent their time in learning dictionary meaning of words really could not use the learned words in sentences. (Contains 2 tables.)