In previous treatments of metal‐semiconductor contact barrier height measurements by the differential capacitance method it has been generally assumed that there exists an Ohmic reference contact to the semiconductor. In this paper, the method is extended to those cases where an Ohmic contact to the semiconductor isnotavailable. It is shown that under certain conditions, barrier heights may be determined using only barrier reference contacts. It is also shown that although only two contacts are necessary, a third contact may be advantageously employed to simplify the measurement technique. If four contacts are available, a further simplification may be achieved.Experimental results on Au&sngbnd;CdS contacts are used to verify the theory for the case of two symmetrical barrier contacts.