Two-dimensional difference gel electrophoresis is an invaluable technique for the analysis of plant proteomes. However, preparation of protein fractions from plant tissues is challenging due to the special features of plant cells: a robust cell wall, large vacuoles which often contain high concentrations of organic acids and a broad range of secondary metabolites like phenolic compounds and pigments. Therefore, protein preparation for difference gel electrophoresis (DIGE) analyses has to be adapted. Here, we describe both a phenolic protein extraction method for plant tissues and an adapted protocol for DIGE labeling of the generated fractions.