The current study investigates the effectiveness of teaching vocabulary learning strategies on students' vocabulary achievement, frequency and varied use of these strategies. The study was conducted with 68 grade nine female students at Hail Al-Awamir School for Basic Education. These students were divided into a control group and an experimental group each consisting of 34 students. Explicit instruction on different vocabulary learning strategies was carried out for 9 days. The task was to introduce new words along with some discovery and consolidation strategies. Tests were given to know how well students remembered words, and a questionnaire was administered to collect data about the variety of vocabulary learning strategies used by the students and the frequency with which they used these strategies after the strategy instruction. Informal interviews were also conducted with some students to obtain their responses to strategy training. In preparation for the experiment, learners' vocabulary learning strategies were elicited prior to the experiment for the purpose of teaching the least used strategies. This also helped with the design of the strategy tasks for this study. Subjects were also pre tested to ensure that the language level of both groups were essentially equal prior to the study. Learners in both groups were post-tested and their scores were compared with their pre-test scores. Findings showed that students in the experimental group outperformed those in the control group. This indicates that strategy based instruction was more effective in promoting learners' vocabulary achievement than the traditional way of teaching vocabulary. The vocabulary learning strategies were identified at the end of the study and compared with those identified prior to the study. Findings showed that, as a result of the strategy training, learners in the experimental group used more vocabulary learning strategies and they used these strategies more frequently than the control group. The findings of the present study provide a number of recommendations for some pedagogical practices related to implementing strategy training in Oman as well as some directions for further research.