Filipino students' scores and performances in international tests such as the Program for International Student Assessment (PISA) indicate the country's performance in Science, Mathematics, and reading which is linked to the level of students’ critical thinking. Interrelated to this, the National Achievement Test found that pupils in Gingoog City Division are quite poorly whose learning outcomes are influenced by its schooling: rural and urban. The Philippines is a country that is composed of many multigrade schools as an alternative to monograde schools. With this, researchers disclose the level of critical thinking as learning outcomes of Grade 6 students in multigrade and monograde classes and figure out if multigrade education is a factor to consider. The study used a causal-comparative design of research and cluster sampling, consisting of four multigrade Grade 6 classes with 44 total respondents and two monograde schools with 46 total respondents in the same district of Gingoog City. For the analysis of data, frequency and percentage were utilized to measure the students' reading critical thinking in multigrade and monograde classes respectively, and Mann-Whitney test was performed to determine the significant difference between the critical thinking levels of both groups. Findings revealed that there is no significant difference in students’ achievement between multigrade and monograde courses. In terms of critical thinking, students in the monograde classroom performed fairly better than the students in the monograde classroom despite of the same quality of instruction. Multigrade education has no impact on critical thinking outcomes. Thus, it is recommended that multigrade implementation be continued as a viable learning alternative to the standard monograde classroom.