The current research aims to identify the effect of the Cornell note-taking strategy on the achievement of chemistry among second-grade female students in government daytime middle schools. Al-Fadhila School was chosen intentionally as its student sample, affiliated with the First Karkh Directorate for the academic year (2024-2025). One of the two classes was then chosen to represent the experimental group, taught according to the Cornell note-taking strategy, and the other class, the control group, was taught according to the traditional method. The equivalence of the two research groups was verified using a set of variables, including chronological age calculated in months, the Raven Intelligence Test, previous achievement in chemistry, and a post-achievement test. The equivalence of the two research groups was confirmed. The researchers prepared the research tool, an achievement test consisting of 39 multiple-choice items and one essay item. This was administered to the research sample after being reviewed by arbitrators to ensure its validity. The reliability coefficient was extracted using the Cronbach's alpha equation. The research found a statistically significant difference at the 0.05 level between the average scores of the experimental group students who studied using the Cornell note-taking strategy and the average scores of the control group students who studied using the traditional method, in favor of the experimental group. In light of this, the research confirmed that the Cornell note-taking strategy contributes to increasing chemistry achievement among second-year middle school students more than teaching using the traditional method. It also emphasized the need to encourage chemistry teachers to use the Cornell note-taking strategy, given its importance in organizing and analyzing information and identifying key ideas, which facilitates retrieval.