The new antibodies can be used for the detection of glycodelin A in frozen and paraffin-embedded decidual and endometrial tissue. One antibody (A87-B/D2) can be used for the detection of glycodelin in endometrial and ovarian tumour tissues. Because glycodelin A is a major secretory endometrial product during the luteal phase, in early pregnancy and in gynaecological tumours, the new antibodies are, potentially, valuable tools for the study of endometrial development and tumour progression.