The aim of the research was to know the effectiveness of contextual teaching technique in teaching English vocabulary at the seventh grade of SMP Gunung Jati Kembaran in academic year 2014/2015. The method of the research was experiment. The samples of this research were 30 students from class VIIA as the control class and 30 students from VIIB as the experimental class. The experimental class was taught using contextual teaching technique while the control class was taught using conventional technique. To collect the data, the writer used a test in the form of multiple choice and gap filling. The writer used t-test as technique of analyzing the data. Based on the data analysis, it was found that t-test score was 3.830 while t-table score at level of significance 0.05 for df 58 is 1.672, so t-test was higher than t-table (3.830> 1.672). It means that contextual teaching technique was effective for teaching vocabulary at the seventh grade of SMP Gunung Jati Kembaran.