The growth of "long" fatigue cracks, in α-β titanium alloy forging, subjected to cyclic stresses, is studied in this paper. The fatigue crack growth rate (FCGR) data were recorded at room temperature, 350, 450, 550 and 650°F using the Direct Current Potential Difference (DCPD) technique. The DCPD method, used in this investigation, was found to record and correlate the potential difference in terms of crack growth rate (da/dN) and Mode I stress intensity factor range satisfactorily. Various factors related to error minimization and calibration equations for compact tension specimens have been elaborated. Also discussed were the means to enhance the accuracy of the data by the DCPD system for elevated temperature fatigue crack growth rate testing.