Seeds may contain different components such as starch and complex carbohydrates that can seriously reduce protein extraction. The proteins in cereal seeds are usually classified in four groups according to their solubility criteria: albumins, globulins, prolamins, and glutelins. They can be specifically extracted. A general procedure for extracting the proteins present in green seeds or immature cereal kernels is given. Then several procedures mostly adapted to cereal seeds are reported for: (1) the whole storage proteins (mostly prolamins and glutelins); (2) the albumins-globulins extracted using salt buffer; (3) the amphiphilic proteins extracted using a phase partitioning process; and (4) the proteins strongly attached to or within the starch granules of the seed endosperm. These procedures have been used for 2-D electrophoresis and proteomic analyses.