BACKGROUND: Aedes aegypti is one of the most vicious mosquitoes, known for its role in several deadly diseases, including dengue fever and Zika. Several strategies have been developed over decades to prevent vector-borne diseases; one of them is insecticide to control the mosquito population. However, this strategy would not last long due to the elevation of resistance, environmental problem, and some issues regarding human health. Natural products have become major options to combat the glitches. Lemongrass (Cymbopogon citratus) has known for its toxic effect on mosquito larva. AIM: The objective of this study was to assess the effect of C. citratus extract against fourth instar of A. aegypti larvae. METHODS: Three extract concentrations, 2.5%, 5%, and 7.5%, were used. The larvicide activity was evaluated at 2, 4, and 6 h. Our data indicated that all concentrations contributed to increase larvae mortality. RESULTS: Lethal Concentration (LC) 50 and LC90 were achieved at 2.5% and 4.1% of extract, respectively. CONCLUSION: C. citratus  extract has a larvicide activity against fourth instar of A. aegypti.