This study aimed to identify the effectiveness of Adey and Shayer model in the acquisition of geometry transformation concepts and spatial visualization among ninth grade students. It used a semi experimental method that was applied to a sample of (60) ninth grade students in basic education. The students were divided into two groups. An experimental group consisting of (30) students was taught using Adey and Shayer model, whereas a control group consisting of (30) students was taught using the traditional method. To achieve the research objectives, the researcher designed a teacher's guide book for unit seven which is about geometry transformation based on Adey and Shayer model. Two tools were applied for this study, which are a test designed by the researcher to examine the students acquisition of geometry transformation concepts, and a standardized test on spatial visualization. The results of this study revealed differences at the level of significance (0.05) between the student's mean scores in the experimental group and control group in both geometry transformation concept acquisition test and spatial visualization test for the experimental group According to the results, the researcher recommended to conduct more studies on Adey and Shayer model with other variables and pay more attention to spatial visualization by providing student's with activities.