Semiotics has recently achieved some prominence as a theoretical foundation for foreign language learning/teaching. Though there have been a number of research on the semiotics in foreign language learning, the practical use of semiotics in preschool classroom environment still remains unanswered. What is more, the effectiveness of computers on vocabulary learning among preschool children is still an obscure area, which attracts the attentions of researchers, scholars and practitioners. Thus, the study aims to investigate if there is any significant difference in preschool children's vocabulary gain depending upon the computer assisted vocabulary instruction or the traditional vocabulary instruction both adopting a semiotic approach. The sample group of the study included 35 preschool children (5-years) who are enrolled in Balikesir University Necatibey Faculty of Education Kindergarten. In this quasi-experimental study, the children were assigned to computer assisted vocabulary instruction group (16) or traditional vocabulary instruction group (19), the experimental and control groups respectively. Before the experiment, the children were given a pre-test, which measured the target vocabulary the children had already known. While the experimental group learned the target vocabulary through computer-assisted instruction, the control group was given the same words via traditional vocabulary instruction. Following the experiment, the same test was given to the children as the post-test. The findings of the present study indicated that both instruction types were effective in teaching vocabulary and that no significant difference was found between the groups regarding their vocabulary knowledge.