  We test the isotropy of radio polarization angle orientations with a robust
and reliable dual frequency polarimetric survey of active galactic nuclei
(AGN). We find that the polarization orientations are consistent with the
assumption of isotropy for scales larger than or equal to $\sim 800$ Mpc. This
provides further evidence of isotropy at large distance scales and is likely to
impose strong constraints on some of the physical mechanisms that may be
invoked to explain past observations of alignment of radio and optical
polarizations at large distance scales.
