The current research explores vocabulary acquisition via extensive input in the L2. The first study reported here was conducted in the Saudi EFL context, where intensive reading is the prominent approach. The treatment used an extensive reading design in which participants were offered a wide range of graded readers at different levels to read from. The second study was carried out on Arab students studying in the UK. The aim of this study was to determine the relative vocabulary acquisition from extensive reading vs. extensive listening. The third study was based on a corpus of 8'4 graded read~rs from the Oxford Bookworms series. It is a replication ofNation and Wang's (1999) study into vocabulary coverage. The objective of this study was to examine potential opportunities for vocabulary learning available in those graded readers. All ofthe three studies were conducted with quantitative measurements, such as the VLT, PET, TOEFL, a word knowledge scale, and a questionnaire. The results of the first study demonstrated that extensive reading had positive effects on the participants' vocabulary knowledge, reading comprehension, reading speed, and attitudes towards reading in the L2. The findings ofthe second study showed that both extensive reading and listening coUld lead to incidental vocabulary learning. However, these gains are very small. The study also indicated that reading may be more advantageous than listening in terms ofvocabulary gains. Finally, the corpus-based study revealed that graded readers are a suitable means of helping learners encounter new as well as old vocabulary; even if they read less than one graded reader a week. The study also demonstrated that reading more texts at different levels would enable learners to meet words quite frequently.