The tomato leafminer, Tuta absoluta (Meyrick), is a major pest of tomatoes in Morocco. Since its spread in the 1970s, chemical control was the main method of control. However, reduced effectiveness of some of the recommended insecticides has been observed since the 1980s. This study aims to propose alternative solutions based on the use of natural products "bioinsecticide" to fight against the tomato leafminer, Tuta absoluta (Meyrick), which is considered a serious threat to tomato production in Morocco and worldwide. To achieve this objective, we evaluated the toxicity of the essential oil of Syzygium aromaticum L. buds against larvae of Tuta absoluta. Bioassays were performed in the laboratory in petri dishes 9 cm in diameter, at an average temperature of 26 ± 2 ° C and a relative humidity of 60 to 70%. The determination the lethal dose 50 (LD50) of this essential oil has been made via an analysis by probit method using the software BioStat Pro 5.9.8. The values of LD50 and LD100 are respectively 0.0047 and 0,0111μl/cm² calculated after fourths hours of exposure confirms the high degree of toxicity of the essential oil of Syzygium aromaticum L. buds on filter paper against the larvae of Tuta absoluta.