The current Covid-19 pandemic is a threat to health and well-being. Washing hands with soap is an effort to prevent Covid-19 as the body's protection from various infectious diseases. The purpose of the study was to determine the effect of education on the behavior of washing hands with soap on disease prevention during the Covid-19 pandemic in preschool-aged children at Al-Muntahar Kindergarten, Lhokseumawe.The design of this research is Quassy experiment, with the design of One Group Pretest and Posttest. The population in the study amounted to 40 students. The number of samples is 40 respondents using total sampling technique. This research was carried out on 03 to 07 August 2021. The analysis was carried out by a computerized process through the paired t test.Based on the results of the study, it was found that the prevention of disease during the Covid-19 pandemic in preschool-aged children before being given education on handwashing with soap was in the category not done (65.0%) and disease prevention during the Covid-19 pandemic in preschool-aged children after being given education. the behavior of washing hands with soap is in the category done (75.0%). The results of the p-value = 0.000 <0.05, it can be concluded that there is an effect of education on the behavior of washing hands with soap on disease prevention during the Covid-19 pandemic in preschool age children.It is hoped that there will be more health education programs, especially about washing hands with soap by delivering counseling that is easily understood by children.   Abstrak Pandemi Covid-19 yang saat ini merupakan ancaman terhadap kesehatan dan kesejahteraan. Mencuci tangan dengan sabun merupakan upaya pencegahan Covid-19 sebagai perlindungan tubuh berbagai penyakit yang sifatnya menular. Tujuan penelitian untuk mengetahui pengaruh edukasi perilaku cuci tangan pakai sabun terhadap pencegahan penyakit di masa pandemi Covid-19 pada anak usia prasekolah. Desain penelitian ini bersifat Quassy Experiment, dengan perancangan One Group Pretest dan Posttest. Populasi dalam penelitian berjumlah 40 siswa. Jumlah sampel sebanyak 40 responden dengan menggunakan teknik totalsampling. Penelitian ini dilaksanakan pada tanggal 03 s/d 07 Agustus 2021. Analisa dilakukan dengan proses komputerisasi melalui uji t-paired. Berdasarkan hasil penelitian didapatkan bahwa pencegahan penyakit di masa pandemi Covid-19 pada anak usia prasekolah sebelum diberikan edukasi perilaku cuci tangan pakai sabun berada pada kategori tidak dilakukan (65.0%) dan pencegahan penyakit di masa pandemi Covid-19 pada anak usia prasekolah sesudah diberikan edukasi perilaku cuci tangan pakai sabun berada pada kategori dilakukan (75.0%). Hasil nilai p-value= 0.000 <0.05, dapat disimpulkan ada pengaruh edukasi perilaku cuci tangan pakai sabun terhadap pencegahan penyakit di masa pandemi Covid-19 pada anak usia prasekolah. Diharapkan agar lebih memperbanyak program-program edukasi kesehatan terutama tentang cuci tangan pakai sabun dengan cara penyampaian penyuluhan yang mudah dimengerti oleh anak-anak.