This thesis focuses on the possibility of vocabulary building by the aid of computers. The major aim is to prove that computer usage can stimulate vocabulary building, and it can be even more efficient than the traditional way. The second aim is to examine the connection of the participating students’ sex and their performance. As a third aim, the connection of the student’s grades and their performance is examined. Altogether 33 Hungarian primary school students were participating in this research: a class of sixth graders (20 students) and a class of eighth graders (13 students). Both classes were divided into two groups: a computer aided group and a control group. The two groups were taught the same vocabulary items, but in a different way. Students had to write an immediate post-test right after the lesson, and a delayed post-test one week after. The results showed that there was no significant difference between the performances of the computer aided groups and the control groups. The difference between the scores on the two tests was negligible. Considering the second and third aims, the results showed that female students performed better under the same conditions, and it also proved that there is a connection between the students’ grades and their performance.