  With the advent of the recent measurements in neutrino physics, we
investigate the role of high-energy neutrino flux ratios at neutrino telescopes
for the possibility of determining the leptonic CP-violating phase \delta and
the underlying pattern of the leptonic mixing matrix. We find that the flux
ratios show a dependence of O(10 %) on the CP-violating phase, and for
optimistic uncertainties on the flux ratios less than 10 %, they can be used to
distinguish between CP-conserving and CP-violating values of the phase at
2\sigma in a non-vanishing interval around the maximal value |\delta|=\pi/2.
