This study investigated the impact of a web-based teaching method on students' academic achievement and attitudes in the elementary education fifth grade Science and Technology unit, "System of Earth, Sun and Moon". The study was a quasi-experimental study with experimental and control groups comprising 54 fifth grade students attending a state school in the 2012-2013 academic year. Lessons in the experimental group of 26 students were taught with the help of web-based teaching materials designed in a computer environment, whilst students in the control group of 28 were taught according to the textbook. Comparisons based on pre- and post-test results were used to identify the impact of the web-based method on student achievement. Findings suggested a significant difference in favor of the experimental group in their achievement in Science and Technology lessons and positive attitudes towards computer technologies and astronomy.