As one of language skills taught at schools in the context of teaching English as a foreign language in Indonesia, speaking skill has been learned at the level of senior high school. However, for most of students speaking is considered as the most difficult skill. This research was aimed at describing the barriers in speaking faced by grade XI students of SMA Negeri 12 Banda Aceh and the causes of the barriers. The design of this study was a descriptive qualitative study. To obtain the data, six students selected by using simple random sampling technique were interviewed. The results of interview in this study shows that all of students faced barriers in grammar, three students were in vocabulary, and two students were in pronunciation. Based on the results it can be concluded that grammar problem and lack of vocabulary knowledge were caused by the laziness, indifference to pay attention, confusing instruction by the teacher and pronunciation was caused by lack of self-confidence and difficulty in articulating English sounds. Therefore, it is recommended that the teachers find the good ways to solve those barriers.