The invention proposes a polarized lightwave reflectometry method which is more accurate and which can be considered as genuinely quantitative, at least over a given range of polarization mode dispersions. For this purpose, the method of the invention may make use in particular of all or some of the following original characteristics: instead of sending a single polarized light signal into the optical fiber to be tested, at least two polarized light signals are sent into the optical fiber to be tested, the signals presenting a determined angular offset relative to each other so that the polarization mode dispersion coefficient remains independent of any rotation of polarization in the optical fiber under test; a preferred value for the angular offset between the two linearly polarized signals being about 45 degrees; instead of extracting scalar parameters of the DGP or DOP type from the trace obtained by back-scattering of the light signal, a scalar parameter is extracted of the relative noise type for each trace obtained by back-scattering of the light signal; and the polarization mode dispersion coefficient is estimated by means of a function having a single scalar input, which function is of the type based on exponentials and has the form exp(a+bP+cP<-1>).