Menurut data BPOM tahun 2019 sekitar 40-45% jajanan anak sekolah tidak memenuhi syarat. Hal ini dapat memperburuk status gizi anak yang dapat mempengaruhi pertumbuhan anak sekolah. Makanan jajanan yang mengandung zat berbahaya dan tercemar oleh mikrooba dapat menimbulkan reaksi akut pada tubuh, yaitu berupa batuk, diare, alergi, kesulitan buang air besar atau bahkan keracunan. Tujuan penelitian untuk menganalisis perilaku jajan anak Sekolah Dasar Negeri 060925 Kecamatan Medan Amplas Desain penelitian yang digunakan adalah survei analitik  dengan rancangan cross sectional. Populasi dalam penelitian ini adalah siswa Sekolah Dasar Negeri 060925 Kecamatan Medan Amplas yaitu berjumlah 102 orang. Tehnik pengambilan sampel menggunakan purposive sampling. Jumlah sampel yang akan diteliti adalah 50 orang. Analisa data dilakukan dengan analisis univariat, bivariat dengan uji Chi Square dan multivariate. Hasil penelitian variabel Pengetahuan diperoleh nilai p-value = 0,001, Sikap = 0,002, Tindakan = 0,001 artinya ada pengaruh penyuluhan kesehatan terhadap Pengetahuan, Sikap dan Tindakan pencegahan jajan diluar kantin Sekolah Dasar Negeri 060925 Kecamatan Medan Amplas. Hasil analisis multivariat didapatkan variabel yang paling berpengaruh dalam penelitian ini adalah variabel Pengetahuan dengan nilai Exp (B) 26.000. Ada hubungan penyuluhan kesehatan dengan pengetahuan, sikap dan tindakan dengan perilaku pencegahan jajan diluar kantin Sekolah Dasar Negeri 060925 Kecamatan Medan Amplas, dari hasil analisis multivariat menunjukkan hasil bahwa faktor penyuluhan kesehatan yang paling dominan adalah variabel pengetahuan. Diharapkan kepada pihak sekolah agar pengetahuan siswa Sekolah Dasar Negeri 060925 Kecamatan Medan Amplas dapat bertambah dan menjadi media diskusi yang dapat menambah daya tarik siswa dalam mempelajari ilmu tentang kesehatan jajanan secara komprehensif.Kata Kunci: Perilaku Pencegahan Jajan Diluar Kantin Sekolah, Pengetahuan, Sikap, TindakanAccording to BPOM data in 2019, around 40-45% of school children's snacks do not meet the requirements. This can worsen the nutritional status of children which can affect the growth of school children. Snack foods that contain harmful substances and are contaminated by microbes can cause acute reactions in the body, namely coughing, diarrhea, allergies, difficulty defecating or even poisoning. The purpose of the study was to analyze the snacking behavior of children at State Elementary School 060925, Medan Amplas District. The research design used was an analytic survey with a cross sectional design. The population in this study was the population in this study were students of the State Elementary School 060925 Medan Amplas District, which amounted to 102 people. The sampling technique used purposive sampling. The number of samples to be studied is 50 people. Data analysis was performed with univariate analysis, bivariate with Chi Square and multivariate tests. The results of the study of the Knowledge variable obtained p-value = 0.001, Attitude = 0.002, Action = 0.001 meaning that there was an influence between health education on Knowledge, Attitude and action on preventing snacking behavior outside the school canteen in State Elementary School students 060925 Medan Amplas District. The results of multivariate analysis showed that the most influential variable in this study was the Knowledge variable with an Exp (B) value of 26,000. There is a relationship, health education with knowledge, attitudes and actions towards preventing snacking behavior outside the school canteen for students at State Elementary School 060925 Medan Amplas District, from the results of multivariate analysis, it shows that the most dominant health education factor is the Knowledge variable. It is hoped that the school will increase the knowledge of State Elementary School 060925 Medan Amplas Subdistrict students and become a discussion medium that can increase the attractiveness of students in learning about the health of snacks in a comprehensive manner. Keywords : Behavior of preventing snacks outside the school canteen, Knowledge, Attitude, ActionÂ