The primary respiratory mechanism (PRM) as manifested by the cranial rhythmic impulse (CRI), a fundamental concept to cranial osteopathy, and the Traube-Hering-Mayer (THM) oscillation bear a striking resemblance to one another. Because of this, the authors developed a protocol to simultaneously measure both phenomena. Statistical comparisons demonstrated that the CRI is palpably concomitant with the low-frequency fluctuations of the THM oscillation as measured with the Transonic Systems BLF 21 Perfusion Monitor laser-Doppler flowmeter. This opens new potential explanations for the basic theoretical concepts of the physiologic mechanism of the PRM/CRI and cranial therapy. Comparison of the PRM/CRI with current understanding of the physiology of the THM oscillation is therefore warranted. Additionally, the recognition that these phenomena can be simultaneously monitored and recorded creates a new opportunity for further research into what is distinctive about the science and practice of osteopathic medicine.