In this work, we developed a new multi-residue method for the analysis of several herbicide classes (e.g. chloroacetanilides, triazines and their main metabolites), insecticide classes (organophosphorous and carbamates) and fongicides classes (triazoles and strobilurines) extracted from soils. Analysis were performed by GC-MS and a large volume splitless injection technique was developed for improving the sensibility. A pressurised liquid extraction (PLE) technique was applied and optimized in order to improve the recoveries for a large range of polarities. This optimization was achieved with the use of experimental designs for the screening of the main factors, and the determination of the response surface and the optimal conditions.