This study was an attempt to investigate the effect of the Peer Review Technique (PRT) in improving students’ English vocabulary. English Vocabulary Improvement (EVI) is an important unit in English subject and the other units are grammar use, pronunciation, writing, reading, speaking, and listening skills. English subject is taught in the Islamic secondary schools in Indonesia by integrating certain elements of various cultures into the School Based Curriculum (SBC). The main focus of this project was to use PRT in teaching EVI after the integration of Cross-cultural curriculum (CCC) into SBC. A class of 40 students having the same level of achievement was chosen for the project. This class was then divided into experimental (20 students) and control (20 students) groups. They were numbered to be selected randomly. The result of investigation proved that the experimental group which was taught English vocabulary using PRT has improved better than the control group which was taught by the conventional approach. The findings of this project indicate that the CCC can be developed to help the teachers’ effort to improve students’ English vocabulary in a plural society.