Cervical ripening is defined as the significant softening of the cervical tissue that usually begins before the onset of contractions during labor, and is required for cervical dilation and delivery. Osmotic dilators are medical implements that dilate the uterine cervix by increasing in size as they absorb fluid from the surrounding tissue. This article aims to review the mechanisms and applications of osmotic dilators for cervical ripening in the induction of labor and in gynecology procedures.