Abstract : The Directorate General of Communicable Disease and Environmental Health Prevention (or PPM-PLP) said that the most effective and appropriate way in preventing and eradicating Dengue Hemorrhagic Fever (DHF) is breaking the first chain with the program called Mosquito Nest Eridication with 3M Plus. This study aims to analyze the effect of Mosquito Nest Eridication with 3M Plus training and accompaniment towards Islamic boarding school students. This type of study is quantitative with pre-experimental one group pre-test and post-test design. This study involved 70 students with purposive sampling technique. Behavior was measured through knowledge using a questionnaire and action using an observation sheet on the presence of larvae in container. Data analysis used Mc Nemar Test. There was a significant effect of Mosquito Nest Eridication training and accompaniment with 3M Plus towards the participants related to knowledge (p = 0.041) while there was no effect on the presence of Aedes aegypti larvae related to action (p = 0.250). Training and Accompaniment had only significant effect on knowledge and not on action related to the presence of Aedes aegypti larvae. Mosquito Nest Eridication with 3M Plus training and accompaniment activities are always expected to increase knowledge of the importance of implementing Mosquito Nest Eridication with 3M Plus and be consistent in its application.