Learning management systems (Moodle) are considered one of the most important learning systems in the world due to their technical and educational capabilities helping to upgrade the level of the educational process. That study aims at verifying the effectiveness of these capabilities on improving skills of critical thinking for teachers while using Moodle systems at designing and managing courses. Study sample was formed of 30 teachers at a prep school in Kafr El-sheikh, Egypt. A card for evaluating skills of critical thinking of teachers was designed by using Moodle system. Results of the study proved a remarkable improvement in critical thinking skills for teachers via exchanging experience and knowledge during the design of courses using Moodle systems.