Objective: To investigate glycodelin (Gd) binding to the surface of sperm cells in relation to sperm morphology and seminal plasma Gd. Design: Retrospective study. Setting: University-based IVF Unit, Department of Gynecology and Obstetrics. Patient(s): A total of 5,749 spermatozoa from 42 patients were analyzed. Intervention(s): Evaluation of sperm cell morphology according to World Health Organization criteria, measurement of Gd binding by an immunocytochemical staining method, scoring of Gd binding per spermatozoon, and assessment of Gd levels in seminal plasma Gd by ELISA. Main Outcome Measure(s): Glycodelin binding per sperm cell was correlated with ejaculate classes, single cell morphology, and Gd in seminal plasma. Result(s): Variability was observed in the scoring of sperm surface Gd binding per ejaculate and of the Gd levels (36.4-578.2 μg/mL) in human seminal plasma. Surface and seminal plasma Gd values showed no correlation in all cases. However, Gd adherance to the sperm surface depended on sperm morphology according WHO-criteria. There was reduced Gd binding to normal-shaped male gametes compared with abnormal spermatozoa. Conclusion(s): Glycodelin binding to human spermatozoa correlates with sperm morphology. The variability of Gd adherence suggests differences in sperm membrane properties according to the quality of the spermatozoa.