The present study aimed at measuring the effectiveness of the use of advance organizers in second grade preparatory student achievement in Arabic grammar. More specifically, an attempt was made in this study to answer the following question: Is there a statistically significant difference between the experimental group students and those of the control group in their achievement in Arabic grammar? Students of the experimental group were taught grammar using advance organizers whereas those of the control group were taught grammar in the commonly used way. To answer this question, two steps were followed: First, a grammar achievement test was designed and its validity and reliability were established. To establish its validity, it was submitted to a number of jury members. Its reliability was also established using Alfa Cronbach (Reliability = 141). Second, a randomly chosen sample comprising 100 second grade preparatory students from the south of Al-Dahra region was divided into two groups: an experimental group and a control one. The experiment lasted for two months during which learners were exposed to 14 periods of grammar instruction. The achievement test was then administered to the two members of the two groups. Data analysis revealed no statistically significant difference between the experimental group and the control group in their achievement in grammar. A number of recommendations were made. More attention should be given to the professional preparation of teachers. Teachers need to be trained to use up-to-date methods in teaching grammar. A number of suggestions for further research studies were also made. It was proposed that further studies could be conducted to investigate the effectiveness of using advance organizers as well as other methods in teaching different language arts.