The objective of the current work is to increase the level of vocabulary in English through the use of language games in the students of 3rd year of primary school of Americana Adventist School, Juliaca. In this sense, the design of  the investigation is quasi-experimental because we worked with two groups: control group and experimental group. The investigation studies two variables: independent variable, the use of language games; and the dependent variable, level of vocabulary. It was worked with a sample of 40 students, of whom 20 belonged to the Control Group and the other 20 to the Experimental Group. These two groups did a pretest before the teaching of vocabulary, and then the treatment (use of language games) was applied just to the Experimental Group while the Control Group continued with the traditional way of learning. After this period (12 lessons) a posttest was applied to both groups in order to compare the results.

The test applied consisted of six sections which measure the four indicators of the variable Level of Vocabulary: recognize, deduce, interpret, and discriminate. The test is evaluated based on the scores provided by the National Curricular Document- Education Ministry.

The analysis of the tables and descriptive analysis show that there is difference between the results obtained in the pre and posttest of the Control and Experimental Group, being the final results of the Experimental Group greater than the ones obtained by the Control Group. This lets us conclude that the use of language games is useful for the increase of vocabulary in the students.