The present study concentrates on the effectiveness of cai package on teaching geometry among high school students. The main objective of the study is to find out the effectiveness of cai  package on geometry teaching among standard ix students. It was proved using Pretest-posttest Equivalent group design – an experiment study. The result of this study reveals that the students of the experimental group show greater achievement not only in the gain scores but also in the attainment of knowledge, understanding and application level.