The research was conducted to determine the effectiveness of SOLO Taxonomy Assessment to Improve the Critical Thinking Skills of Grade 9 TLE – Drafting Learners. This study utilized a quasi – experimental research design which implement SOLO taxonomy assessment to forty – four (44) drafting students during their 2nd grading period of S.Y 2024 – 2025. Pre – test and post – test was administered to test the significant increase in their critical thinking skills. This study is limited in the use of SOLO Taxonomy as an assessment in learners critical thinking skills focused on analyzing, synthesizing, and evaluating. This research paved the way to improve students critical thinking skills by exposing the learners to SOLO Taxonomy based questions. The results revealed that students had a significant increase in their level of critical thinking skills when SOLO taxonomy as an assessment was used. Moreover, the highest increase was seen in analyzing, followed by evaluating, while synthesizing shows the lowest, but still significant. Furthermore, if the students were exposed to SOLO taxonomy assessment it enhances the critical thinking skills of the student.