School regulation is the important thing to enhance students discipline at school. The school needs to implement the school regulation in a right way and to make sure that all entire school citizens obey the regulation. This study purposed to investigate the correlation between school regulation enforcement and students’ discipline at Vocational School in Yogyakarta. Besides, this focuses of this study aimed to know the level of school regulation enforcement, the level of students’ discipline, and also to identify the relation between school regulation enforcement and students’ discipline. The data were gathered from the students of Senior High School students at Vocational School in Yogyakarta. A descriptive quantitative research design was used as a research method of this study. The populations were 132 students of this study. The data were gathered using the questionnaire. The result showed that the level of school regulation enforcement at Vocational School in Yogyakarta was in good level category with the mean score 28.72, and the level of students’ discipline was in a very high level category with the mean score of 32.17. The last result of the study was that there was a positive significant correlation between school regulation enforcement and students’ discipline. Likewise, the result of the Pearson Correlation was 0.340 with the significant correlation score of 0.00. Therefore, this research showed that good school regulation enforcement at school will give advantages to the students’ discipline at school