This study examined the effects of using computer word/grammar processor on Iranian elementary students' spelling and grammar improvement. To this end, the researcher administered the Oxford Quick Placement Test (OQPT) to 80 Iranian EFL learners to determine their level of English proficiency. The researcher selected 50 elementary students and divided them into two experimental groups; spelling group (n=25) and grammar group (n=25). Then, both groups were pretested. After that, the participants of both experimental groups received the treatment; they were taught through computer word processor. In the spelling group, 10 laptops were available for teaching spelling through using Computer Microsoft Word Processor. Some words and sentences were read by the researcher and the students were asked to type them through Computer Word Processor in the Computer The results of paired and independent samples t-tests revealed that both experimental groups had better performance on their post-test compared to their pre-test. The results showed that there was not a significant difference between the performances of the two experimental groups on the post-test. Finally, implications arising from the findings and suggestions for further research were explained.