Thai students at English Language Education Department (ELED) still have difficulties in learning English vocabulary. This makes them struggle in their reading, writing, speaking as well as listening. Knowing their problems and strategies will help them solve their difficulties. This research aimed to identify the general strategies of Thai students in learning English vocabulary. Then, it also aimed to find out the problems faced by Thai students as well as their strategies specifically used to solve their problems in learning English vocabulary at ELED at a private university of Yogyakarta, Indonesia. This research belongs to descriptive qualitative research. The participants of this research were four Thai students who had learned English for four to six semesters, and had problems related to vocabulary. The researcher used interview to collect the data. The findings showed that generally Thai students used various strategies in learning English vocabulary. The findings also revealed that students had problems in learning English vocabulary namely: advanced lexicon, forgetfulness, synonym of a word, pronunciation, British or America lexicon, and feeling lazy. To overcome these particular problems the participants used some strategies. The certain strategies are using dictionary, memorizing word, practicing and repeating, writing down the word, making a sentence, using the Internet and listening to music or video of native speaker. Most of the strategies they used were the strategies they already know and felt useful.