Literature data on the diffusion behavior at infinite dilution, as measured with dynamic light scattering, of flexible highly charged polyelectrolytes were collected, The apparent diffusion coefficients extrapolated to zero polyelectrolyte concentration were investigated for different molar masses and ionic strengths. The experimental values were compared with theoretical D-0 values calculated with a theoretical procedure based on the wormlike chain model of Yamakawa and Fujii for the translational friction coefficient. The electrostatic persistence length according to Le Bret and the excluded volume theory of Fixman and Skolnick were applied. With the hydrodynamic expansion factor of Barrett and the counterion condensation theory of Manning, satisfactory agreements were found for D-0 values measured at moderate and low ionic strengths, Significant deviations occur at high ionic strength (3.1 M), For flexible polyelectrolytes in the ionic strength range from 0.001 up to 0.5 M the ionic strength dependence of the electrostatic persistence length shows a scaling behavior close to kappa(-1). The electrostatic persistence length appears to be molar mass independent.