Structure of human cervical mucus plays a pivotal role in female fertility and protection of reproductive health. Investigation of biochemical and biophysical structure of cervical mucus remains a challenge due to complex structural proteins, high content of oligosaccharides and cyclic variability of its structure. We present the current knowledge on chemical and biophysical features of cervical mucus and regulation of its secretion, relevant clinical observations and underexplored elements. The latter relates to biochemical background of physical properties and antimicrobial activity of cervical mucus, and regulation of its production.