Abstract:This study aims at investigating the correlation between language learning strategies (LLSs) and writing achievement, the correlation between motivation and writing achievement, and the correlation between LLSs combined with motivation and writing achievement. It involved onehundred English as a foreign language (EFL) students of a senior high school which is located in a big city in Indonesia. The students were selected randomly to be the participants of this study. The data were collected by using the Strategy Inventory for Language Learning (SILL) questionnaire, motivation questionnaire, and writing tests. The results of research revealed that the null hypotheses for the three correlational analyses were rejected. In other words, there is a significant correlation between LLSs and writing achievement; there is a significant correlation between motivation and writing achievement; and there is a significant correlation between LLSs combined with motivation and writing achievement. Theoretically, this study supports the important roles of LLSs and motivation, either separately or combined, in predicting writing achievement. Pedagogically, when teaching writing, EFL teachers are recommended to introduce the potential of LLSs to EFL students, arouse the students' motivation to write, or to apply both of them simultaneously to boost EFL students' writing achievement.