An investigation of the thermal contact conductance between a standard fiberglass laminate and steel and aluminum was made. Also, to determine the significance of the contact conductance, two fiberglass samples were bonded to metal samples and one fiberglass sample was layed up directly on a metal sample. Surface finish of the metallic specimens was intended to be representative of standard engineering call outs. Values of 125 RMS, 32 RMS, and "as received" were used. Surface finish of the fiberglass was per an industry specification. Tests were conducted at both atmospheric pressure and at vacuum to measure the amounts of solid and gaseous conduction across the test interface. Test data were found to show trends in correlation with theory. Results are plotted graphically as a function of applied mechanical pressure. The maximum value of solid conductance was found to be obtained when the samples are joined directly together by either bonding or direct layup.