Abstract The present study investigated the effect of graphic organizers on writing performance and attitudes of Omani grade Eight EFL students. The study was quasi-experimental in nature, and the population of the study consisted of grade eight basic education cycle two students in the academic year 2011 2012. Two grade eight classes from a school in Batinah South region of a total of fifty eight students represented the study sample. One class (29 students) represented the experimental group, which taught writing using graphic organizers. The other class (29 students) represented the control group, which was taught writing following grade eight course book methodology in teaching writing. Three instruments were used in this study. A writing achievement test was used to measure the student's level in writing. An attitude questionnaire was used to assess the groups (experimental and control) attitudes towards writing. Another attitude questionnaire was used to measure the attitude of the experimental group students towards using graphic organizers in writing, The major findings of the study are as follows: The results of the achievement test revealed a significant difference between the learners' achievement of the experimental group and the learners' achievement of the control group using t-test that favored the experimental group who used graphic organizers in writing. This finding indicates that using graphic organizers in writing was effective. Following the completion of the course, the results of the questionnaire on attitudes towards writing showed that learners showed positive attitudes towards writing. The results of the questionnaire on attitudes towards using graphic organizers in writing revealed that students (experimental group) retained very positive attitudes towards using graphic organizers in writing. In the light of these findings, recommendations and suggestions for further research are outlined.