Penelitian ini bertujuan untuk mengetahui efektivitas model pembelajaran kooperatif tipe Team Assisted Individualization (TAI) dengan pendekatan matematika realistik dalam pembelajaran matematika siswa kelas VII SMP negeri di Sengkang. Populasi penelitian ini adalah seluruh siswa Kelas VII di salah satu SMP Negeri di Sengkang dan dipilih 1 kelas secara acak sebagai sampel penelitian. Pengambilan data dilakukan dengan menggunakan lembar observasi keterlaksanaan pembelajaran, tes hasil belajar, lembar observasi aktivitas siswa, dan angket respons siswa. Hasil analisis statistika deskriptif menunjukkan: (1) persentase keterlaksanaan pembelajaran sebesar 95%, (2) rata-rata hasil pretest yaitu 24,32 dan rata-rata posttest yaitu 83,92, (3) ketuntasan klasikal tercapai yakni sebesar 86%, (4) rata-rata gain ternormalisasi sebesar 0,78 (kategori tinggi), (5) persentase aktivitas siswa sebesar 92%, (6) persentase siswa yang memberi respon positif terhadap pelaksanaan pembelajaran sebesar 86%. Hasil analisis inferensial menunjukkan: (1) nilai rata-rata siswa yang diajar lebih besar dari 75 (KKM), (2) nilai rata-rata gain ternormalisasi lebih besar dari 0,3. Dari hasil penelitian ini dapat disimpulkan bahwa pembelajaran dengan model pembelajaran kooperatif TAI dengan pendekatan matematika realistik efektif digunakan pada siswa Kelas VII SMP Negeri di SengkangKata Kunci: Efektivitas, Model Pembelajaran Kooperatif tipe Team Assisted Individualization, pendekatan matematika realistik. This research aims to determine the effectiveness of the cooperative learning model type team assisted individualization (TAI) with realistic mathematic approach at Grade VII SMP Negeri in Sengkang. The population of this research were all students of Grade VII in one of SMP Negeri in Sengkang and one class selected randomly as the research sample. Data collection was performed by using the observation sheets of learning accomplishment, learning achievement test, observation sheet of students’ activity and questionnaire of students’ responses. Descriptive statistical analysis of the results showed: (1) Percentage of learning accomplishment approach is 95% ( well done), (2) the average of pretest is 24,32 and the average of posttest is 83,92, (3) classical completeness is reached 86%, (4) the average normalized gain is 0,78 who are at high category, (5) Percentage of students’ activity is 92%, (6) the average percentage of students who gave positive response to the implementation of learning is 89%. Inferential analysis results showed: (1) the average percentage of students who is taught approach greater than 75, (2) the average value of normalized gain greater than 0,3. From these results it can be concluded that learning with cooperative learning model type TAI with realistic mathematic approach effective used in students at Grade VII SMP Negeri in SengkangKeywords: Effectiveness, Cooperative Learning Model type Team Assisted Individualization, Realistic Mathematic Approach.