This article evaluates effectiveness of Google Earth (GE) as an educational tool in secondary school geography lessons and whether it contributes to students' achievement. A GE exercise was developed regarding the types of coastal formations. It was implemented in a ninth-grade geography lesson in three high schools in Turkey. The students followed the exercise from a printed set of instructions and entered the same steps on their computers. Pre-and post-tests were used to evaluate the effects of the GE exercise on students' achievement. A self-assessment form was also used to obtain students' opinions regarding GE and the exercise. This study revealed that the GE exercise was followed accurately and understood by the majority of the students in all the three schools. Students' overall achievement varied with average scores of 9.8 and 24.2 points in the pre- and post-tests, respectively. The majority of the students liked the GE exercise and found it useful and engaging. As is evident from this study, GE is an effective educational tool for secondary school geography lessons, especially when used with proper methods, materials, and objectives.