Dissertation (MA Linguistics)The purpose of this study was to evaluate the effectiveness of vocabulary teaching and learning towards the improvement of learners’ English language skills in Urban West Zanzibar. The study was guided by three objectives. The first objective was to identify the various VLS that the English language teachers use in teaching vocabulary in the English language classroom. The second objective was to assess the extent to which vocabulary teaching and learning helps in improving the English learners’ language skills. The third objective was to examine the challenges that the English language teachers and students face in the vocabulary classroom. The Input Hypothesis Theory of Stephen Krashen (1980) and the Output Hypothesis Theory of Swain (1985) guided the study. The study was conducted in 15 sampled schools located in Urban West Zanzibar. The study employed both qualitative and quantitative methods of data collection and analysis whereby the questionnaire, interview and observation techniques were used for data collection. The findings from the study revealed that the English language teachers in Urban West Zanzibar were aware of various VLS and most of them used contextual guesswork strategies in English language vocabulary classrooms. Low level of improvement in students’ English language skills was observed. Moreover, the findings identified some challenges that hinder the effectiveness of vocabulary instruction in secondary schools in Zanzibar, which were identified as the teacher related challenges, the student related challenges and the education system related challenges. The study ends up by suggesting some corrective measures that could be used to improve the quality of English language teaching and learning especially vocabulary instruction in secondary schools in Zanzibar.