This chapter focuses on sample preparation procedures for pesticide analysis of food commodities, biological and environmental matrices. This will include pesticides with a broad range of polarity including those that are more amenable to gas chromatography-mass spectrometry (organochlorines, organophosphorus pesticides, and pyrethroids) and those commonly analyzed by liquid chromatography-mass spectrometry (carbamates, azole, and strobilurin fungicides, and phenylureas as well as organophosphorus pesticides). QuEChERS (quick, easy, cheap, effective, rugged, and safe) methods or QuEChERS methods with modifications to allow wetting of the dry sample matrix, buffering, changing extraction solvent from acetonitrile to ethyl acetate are examined. Subsequent cleanup using dispersive solid phase extraction or cartridge format solid phase extraction has also been completed to reduce matrix effects. Other solid matrices are frequently extracted with pressurized liquid extraction, microwave assisted extraction, or ultrasonic extraction combined with or followed by dispersive solid phase extraction or solid phase extraction. Particularly for chromatography-mass spectrometry, careful consideration of matrix effects needs to be made when considering the design of the sample preparation procedures. Selection of extraction solvent needs to consider both polarity of target analytes (and their solubility in selected solvents) as well as co-extracted matrix components.