The essential oil and citral content showed significant differences when lemongrass was harvested at different maturity stages. The optimum percentage of essential oil was obtained when lemongrass was harvested at 5.5 months after planting. There were 65 chemical compounds detected in the essential oil of lemongrass. However, only 13 of the compounds were present in each maturity stage. The percentage citral content and percentage composition of geranial and neral were higher when lemongrass was harvested at 6.5 months after planting. The estimated optimum percentage of citral content was obtained at 6.7 ± 0.3 months after planting. Thus, lemon- grass should be harvested between 6.5 to 7.0 months after planting to achieve optimum essential oil with a high composition of citral.