History and custom have decreed a choice of child birth position assumed during labor and delivery. The most common position throughout the centuries has been some form of the upright position, until the mid-seventeenth century when the obstetrician decided that the recumbent position was easier for forceps deliveries. In the nineteenth century, ether was used as an anesthetic by inhalation. The parturient turned on her side to aid the conduct of labor and delivery under anesthesia. From that time on, the birth positions which more easily lent themselves to the convenience of the accoucheur became the choice of childbirth position, and this practice spread throughout most of Western Europe and America. However, literature reveals that the evidence had been available for several decades as to the physiological advantages of labor and delivery in the upright position. And the studies of the process of labor and delivery suggested that certain principles of physics apply to childbirth. Furthermore, the influence of position on the profile of the childbirth process has been studied toxographically and radiographically. Based on the research findings and various studies, the normal parturient should be allowed and encouraged to follow her own instincts and assume that position which will assist her to attain maximum comfort and physiological advantage during her labor and delivery.