Abstract The field of lymphatic research has benefited enormously from the recent discovery of “marker” proteins that permit not only the identification and quantitation of lymphatic vessels in tissue sections for tumour pathology but also the isolation of primary lymphatic endothelial cells for basic research. This chapter focuses on the use of these markers for the immunohistochemical analysis of lymphangiogenesis in both frozen and paraffin-embedded tissue sections and discusses current protocols and their associated problems.