The current study aims to identify the effectiveness of the Team Assisted Individualization Strategy in intelligent thinking in physics among sixth-grade scientific-stream students by verifying the null hypothesis, which states: There is no statistically significant difference at the 0.05 level between the mean scores of the experimental-group students taught according to the Team Assisted Individualization Strategy and the mean scores of the control group taught by the conventional method on the intelligent-thinking test. The researcher randomly identified the study population from the sixth-grade scientific-stream students at Al-Nasr Central Preparatory School for Boys, affiliated with the Directorate of Education in Al-Najaf Al-Ashraf Governorate, for the academic year (2025-2026), first semester, in physics. Two sections were selected out of eight sections, with a total of (96) students distributed into two sections: (48) students in the experimental group and (48) students in the control group. The equivalence of the two research groups was established for the variables of age in months, intelligence, and prior information. A set of experimental teaching plans was prepared for the two groups, with (16) plans for the experimental group and (16) plans for the control group. An intelligent-thinking test was prepared, consisting of five skills and (20) items for the whole test; each skill included four items. The face validity, construct validity, and item discrimination power of the test were verified. The Kuder-Richardson formula was also used to calculate reliability for the multiple-choice items. The researcher assigned one of the school teachers (Mr. Bashar Mohammed Hassan) to implement the experiment during the first semester of the academic year (2024-2025), as he is one of the physics teachers at the school where the experiment was applied. This was done after the steps of the strategy were explained to him in detail, the teaching plans were presented to him, and continuous communication with him was maintained. After the experiment was completed, the study data were processed using the Statistical Package for the Social Sciences (SPSS). The results showed a significant superiority of the students of the experimental group (Team Assisted Individualization Strategy) over the students of the control group in intelligent thinking; therefore, the null hypothesis was rejected, and the study concluded with a set of proposals and recommendations.