Perilymphatic and endolymphatic pressures were measured consecutively in th
e normal guinea pig using a WPI 900A micropressure system. The mean (n = 10
) perilymphatic and endolymphatic pressures were 2.26 and 2.31 cm H2O, resp
ectively. There was no statistically significant difference between the pre
ssures of the endolymphatic and perilymphatic compartments. The measured va
lues were within the range of pressures found in the literature.