This study describes how Twitter (a social networking tool) was implemented as part of a foreign language Reading Comprehension course; it reports on the students' perspectives and opinions about their experiences. The participants were 52 level 2 learners studying in the English department at Huraymila College of Science and Human Studies. The purpose of the treatment was to ascertain improvements in vocabulary acquisition. The participants were given a pre-test before they were exposed to use of Twitter and a post-test six weeks later. The results revealed that the experimental group performed better than the control group. There were significant differences that favoured the experimental group, in terms of word meaning, spelling, the grammatical behaviour of the words, and the total score. In addition, a questionnaire was administered to the Twitter users to investigate their attitudes and motivation. Students in the experimental group demonstrated a positive attitude towards using Twitter. Therefore, this study suggests that integrating social networking tools into the foreign language learning setting can improve students' vocabulary. Appended to the study are: (1) Pretest and Posttest and (2) Survey Questionnaire.