ABSTRAK Salah satu aspek dasar kesehatan anak adalah kebersihan tangan. Tingkah laku anak yang senang bermain dan sering berinteraksi langsung dengan lingkungan dapat terpapar bakteri yang dapat menempel pada tangannya. Pengabdian masyarakat ini bertujuan untuk Menginplementasikan tindakan mencuci tangan pada anak usia SD. Metode kegiatan dilakukan dengan teknik informing, Modelling, Role Playing, Performance Feedback, dan Transfer Training). Hasil kegiatan pengabdian masyarakat menunjukkan bahwa Pengetahuan tentang mencuci tangan setelah informing dan modeling meningkat menjadi 100% pada kategori baik. Hasil Role Play menunjukkan bahwa para siswa mampu menerapkan langkah-langkah prosedur mencuci tangan secara nyata sesuai dengan materi yang telah diajarkan. Kegiatan role play dan Transfer training mampu membiasakan perilaku mencuci tangan dalam kehidupan sehari-hari saat berada di sekolah maupun di rumah; Indeks Massa Tubuh pre test sebagian besar berada pada kategori kurus berat (94,3%) dan hanya 5,7% yang memiliki Indeks Massa Tubuh normal. Sedangkan Indeks Massa Tubuh post test sebagian besar berada pada kategori kurus berat (94,3%) dan hanya 5,7% yang memiliki Indeks Massa Tubuh normal Kata Kunci: Pengetahuan, Mencuci Tangan, Indeks Masa Tubuh ABSTRACT One of the fundamental aspects related to children's health is the issue of hand hygiene. The behavior of children who like to play and often interact directly with the environment certainly has the potential to be exposed to bacterial germs that can stick to their hands. This community service aims to implement the action of washing hands in elementary school age children. The method of activity is done by informing techniques, modeling, role playing, performance feedback, and transfer training). The results of community service activities showed that knowledge about hand washing after informing and modeling increased to 100% in the good category. Role Play results show that students are able to apply the actual hand washing procedure steps according to the material that has been taught. Role play and transfer training activities are able to familiarize hand washing behavior in daily life while at school or at home; Most of the pre-test Body Mass Index were in the heavy weight category (94.3%) and only 5.7% had a normal Body Mass Index. While the Body Mass Index post-test was mostly in the category of severe underweight (94.3%) and only 5.7% had a normal Body Mass Index.Keyword: knowledge, Hand Washing, Body Mass Index