As the only female god of note to be worshipped by the Slavs, Mokos assumed a broad range of divine roles. She was first and foremost a symbol of the earth's fertility. During the early spring, it was taboo to spit on or strike the ground, since Mokos was said to be pregnant then. Holidays were dedicated to her in the autumn, after the harvest. The belief that Mokos invested the earth with divinity was reflected in peasant practices that, in some parts of Russia, Ukraine, and Belorussia, persisted into the 19th century: the swallowing of a lump of soil to consecrate wedding vows, the placing of earth upon one's head to seal oaths, the confession of one's sins to a hole in the ground instead of a priest.
Over time, Mokos became a patron of women, especially those bearing children or giving birth. She oversaw women's work, such as spinning and weaving. By some groups, such as the Czechs, her name was invoked in times of drought. She was also thought to protect flocks of sheep. The strength of her cult remained substantial, even after the Christianization of the Slavs; as late as the 17th century, Orthodox priests attempted to uncover Mokos-worshippers among the peasantry, asking women whether or not they had "gone to Mokos." In Russia, Mokos was partially absorbed into Orthodox worship, in the guise of St. Paraskeva-Piatnitsa ("Paraskeva-Friday"), whose name day fell in late October, around the time of Mokos's former harvest celebration.