This study aimed to investigate the correlation between the tenth grade students’ writing self-efficacy and their writing achievement and investigated the influence of the tenth grade students’ writing self-efficacy on their writing achievement at SMK Bina Karsa Sriwijaya Tugu Mulyo. The design was a quantitative research. The sample of this study was taken from all the population at the tenth grade consisting 31 students. The data were obtained from Self-Efficacy for Writing Scale (SEWS) questionnaire and writing test. Pearson product Moment Correlation and regression analysis were administered to find out the correlation and the influence between variables. The result indicated that there was no significant correlation between the tenth grade students’ writing self-efficacy and their writing achievement with r obtained (.336) was lower than r-table (.367). Then, the level of probability (p) significance (sig.2-tailed) was .065 was higher than 0.05. From the result of correlation analysis, it can be stated that (Ha) was rejected and (H0) was accepted. Thus, it was not necessary to conduct further investigation to find out their influences. Keywords: Correlation, Writing self-efficacy, Writing achievement