Two Stay Two Stray (TSTS) is an instructional technique that can be applied in all courses and with students of any age. By employing the Two Stay Two Stray technique, this study aims to examine whether there is a significant influence on the vocabulary mastery of fourth-grade students at SD N Ledug, Banyumas. This type of research is quantitative using a quasi-experimental method with a pretest-posttest control group design. Simple random sampling was used in this study, with class IV B as the experimental class and class IV C as the control class. The pre-test data indicated that both classes had low scores; 36.80 and 36.92. Then, the results of the experimental class outperformed the control class in terms of average post-test scores. The control class’s average was 69.64, while the experimental class's average was 82.08. The data analysis techniques used were T-Test, and N-Gain. Based on the results of the analysis of the independent t-test, which yielded a value of 0.008 < 0.05. Then, the N-Gain test results show that the Two Stay Two Stray technique is quite effective, with an average percentage value of 75% Compared to the control class, which had an average percentage value of 54% and a less effective interpretation. Consequently, H0 is rejected, and Ha is accepted. In conclusion, there is a significant influence on students’ vocabulary mastery with TSTS techniques in 4th grade of SD Negeri Ledug, Banyumas.