Myrtle, Myrtus communis L., is an herb widely used throughout the world. It is one of the most popular plants in Morocco. For the purpose of examining the factors affecting extraction of this plant’s essential oil by hydrodistillation, a screening study by Hadamard matrix type Placket and Burman was conducted. After an appropriate choice of seven variables, sixteen experiments lead to a mathematical model of first degree linking the response function (yield) to factors. After the experiment’s realization and data analysis, we concluded that five factors have a significant effect on the hydrodistillation process, namely: the extracting time, the individuality effect, the harvest period, the material/water ratio and the heating temperature with the coefficients: 0.041, 0.025, - 0.021, 0.018, -0.015 respectively. Moreover, the plant material’s drying and cutting present a statistically negligible effect.