Sex education is still a taboo topic to be discussed in children’s lives. It is due to the lack of knowledge about sex education itself and the concern about the psychological readiness of children to receive sex education. Therefore, this study aims to analyze the need for sex education from the perception of elementary school teachers. Participants in the study involved four (4) voluntary teachers of the Lantan public elementary school in Lombok, West Nusa Tenggara. The study’s design is a case study in which the data analysis uses Miles and Hubberman models such as data reduction, data display and conclusion drawing. Online interviews were applied to collect data. The study’s finding is the definition of sex education according to the perception of elementary school teachers. Sex education does not teach about sex literally. However, it is an activity to teach children about reproductive health, sex and its consequences, and information on how to avoid sexual violence. Analysis of the needs of sex education for elementary school students indicates that elementary school students should learn about sex education from an early age. However, there are differences in class levels in determining when children should comprehend sex education. This study also found several methods in teaching sex education such as lecture methods, using media such as videos, group discussion and storytelling. This study will also help elementary school’s teachers find solutions related to teaching sex education for children. Teachers’ perceptions showing positive things about the needs of sex education can also reduce stigma in society regarding sex education which is still considered taboo for elementary school students.