Forty-eight endometrial biopsy specimens were obtained during a normal menstrual cycle, during pregnancy and from patients with dysfunctional bleeding. The specimens were examined for Peanut (PNA), Soybean (SBA), Vicia villosa (VVA), Phytohem- (PHA), Lens culinaris (LCA) and Concanavalin (succ. Con A) agglutinin binding. The study was performed on paraffin sections using the pronase digestion and either the peroxidase-antiperoxidase or the avidin-biotin-peroxidase method. Cycle-related changes of the PNA, SBA, VVA, and to some degree PHA binding, were based on the transfer of the cytoplasmic reaction toward the glandular lumena. PNA + and SBA + material moved to the cell surface at the transition of the follicular and luteal phase and before the basal vacuolization appeared. Functional disturbances mainly influenced the intensity of the reaction. It was true only for those lectins, whose binding pattern showed cycle-related changes. In curettings from patients with a prolonged menstrual cycle the lectin binding seen in normal late secretory endometrium was absent or significantly diminished. Lectin binding to the endometrial surface epithelium was variable; PHA was the only lectin, the binding pattern of which followed cyclic changes in the glycocalyx, detected previously by means of PAS and alcian blue methods.