With the detection of the properties of DDT in the mid 1940’s, the intensive use of pesticides in the agriculture increased 50-fold within the last 50 years of the 20th century. Since pesticides are possibly persistent, accumulate in the food chain and potentially harmful to humans, their meticulous monitoring and regulation as residues in foodstuff and environmental samples is necessary. Ideally the detection of pesticides should be conducted with multiresidue extraction methods combined to selective and sensitive devices like gas chromatography (GC) or liquid chromatography (HPLC) coupled to mass selective (MS) detectors. The goals of this study were to simplify, broaden and validate the actual methods for the extraction and determination of pesticides in food and environmental samples with GC-MS and HPLC-MS. The extraction methods used were the DIN EN 12393, the QuECheRS, a pressurised liquid extraction (PLE) and a ultrasonic solvent extration (USE) methods. The GC-MS and HPLC-MS analysis of pesticides with the QuECheRS method in foodstuff and leaf samples was reliable, repeatable and accurate. The limits of detection were ranging from 1 to 400 g.kg-1 and not yet meeting the authorised values of 10 g.kg-1 required for organic farming samples. The analysis of pesticides from soil samples showed that the best extraction method was the QuECheRS whereas the USE was the worst. Neither the DIN EN 12393 nor the PLE gave sufficient results for polar pesticides and were not applicable for their extraction. The thermodesorption injection for the analysis of pesticide residues with GC-MS was satisfying wih volatile substances but showed a carry-over for less volatile substances. The comparison of 3,300 samples indicated that the number of conventional farming samples with residues or exceeding maximum residue levels (MRLs) decreased between 2004 and 2005, but the number of organic farming samples with residues doubled.