This study compares the inquiry competence of the 8th-grade students participating in the science and environmental education program GLOBE in the Czech Republic with a sample of students of the same age not participating in the program from the Slovak and Czech Republics. Inquiry competence is analyzed as a set of variables representing students' investigation skills, understanding of the procedure of the scientific work, their understanding of the principles of scientific work, and their interest in science. While no differences between the Czech and Slovak students not involved in the GLOBE program were found, the Czech participants achieved a higher level of inquiry competence in most of the investigated variables. Gender was an important factor for both the groups not participating in the program, while no significant difference between boys and girls was found in the group of participants.