This research aimed at investigating the effect of using intelligent tutoring system on teaching English vocabulary for third grade primary stage pupils. The participants of the research included (60) third grade primary stage pupils from El-Dawa primary schools, Beni-Suef. The participants were randomly assigned to form two groups; one to be a non-treatment group (30) and the other to be a treatment group (30). The quasi- experimental design was used in the study. The data were collected by the researcher using a vocabulary test in English language. Findings showed that the participants of the treatment group outperformed those of the non-treatment group in learning vocabulary, indicating a significant effect of the strategy in this regard. The research results also showed that there was a strong positive change in the participants' vocabulary learning and this change appeared in their post test marks. The research presented some recommendations and suggestions for further research.