ABSTRACT : The study reported in this thesis investigated whether the use of graded readers promoted incidental vocabulary acquisition and retention in a Bahraini intermediate school; It also explored student and teacher perceptions of the Graded Reader Program. The study sought to answer the following questions: (1) What effect, if any, does the Graded Reader Program have on students' incidental vocabulary development? (2) What effect, if any, does the Graded Reader Program have on students' vocabulary retention? (3) What perceptions do the students and teachers have of the use of the graded readers for English language learning in general? (4) What perceptions do the students and teachers have of the use of the graded readers for incidental vocabulary learning? The participants of this study were 35 female second intermediate students and 28 female English language teachers. The data for this study was gathered in multiple ways. An experiment was used to collect data on the Graded Reader Program's effect on incidental vocabulary learning and retention. This was done through the use of a vocabulary knowledge scale test functioning as the pre-test, posttest, and retention test. Questionnaires and focus groups were used to explore the students' and teachers' perceptions of the Graded Reader Program. The results of the study revealed that the use of the Graded Reader Program promoted the acquisition of new, vocabulary; moreover, it assisted the retention of these new words for a two-month period. The student and teacher perceptions of the Graded Reader Program were found to be very positive.