A technique for the phase calibration of interferometric meteor radar systems is presented. This technique uses phase differences of meteor echoes measured between spaced receiving antennas. The technique can be applied to data collected during routine observations, effectively allowing self phase calibration without the need for additional hardware or scheduled down time for off-line phase calibration measurements. The technique can also be used to correct data collected using erroneous phase calibration estimates. Simulations of typical range and angle of arrival distributions are used to illustrate the technique and verify its performance. The results reveal that the phase offsets can be estimated to within 2¿ using realistic simulation parameters. The technique is also applied to data collected using the Buckland Park meteor radar, with the standard deviation of the daily phase offsets estimated over a four month period found to be less than 3¿.