The study aims to identify the effect of using word processor in teaching writing skill among secondary students in private schools in Jordan, clear out the differences in writing skill between the control group taught in the ordinary method and the experimental group taught using word processor. The study follows the descriptive and experimental approach to identify the effect of using word processor in teaching writing skills among secondary students in schools in Jordan. The study sample selected in random way consisted of 30 in Al-Jubaiha secondary school in the second semester (2018/2019). The study found that there are significant positive differences in the achievement of the students (experimental group) in writing skill as a result of using word processor in their teaching. The study also found that there are significant positive differences in the achievement of students (experimental group) in spelling and grammar because of the use of word processor in their teaching. This indicates the effectiveness of the word processor for the ninth grade students in writing skills. In the light of the results, the study recommends the use of word processor for teaching because of its effect on the achievement of the ninth grade students in writing skill.