The present study compared the effects of isolated and integrated form-focused instruction (FFI) on the learning of vocabulary in reading passages. Their effects were also compared to those of incidental exposure on vocabulary learning. It further investigated whether such effects would differ depending on the types of vocabulary assessments. To this end, 80 college students in reading-oriented classes received either isolated or integrated FFI treatments over four 50-minute sessions. They also took the pretest and posttest designed to measure their vocabulary learning. The vocabulary tests consisted of two assessment types: one without contexts and the other provided with contexts. The results showed that the learners remembered the words instructed through isolated or integrated FFI better than those through incidental exposure while reading. However, no significant differences were observed between the two different types of FFI in learning target vocabulary. Some advantages were found for isolated FFI on the vocabulary test provided without contexts and for integrated FFI on the vocabulary test provided with context. Directions for further studies and pedagogical implications will be discussed.