Neutrinos may possess tiny magnetic moments ($\mu_{\nu}$) via quantum corrections, by virtue of which they can undergo spin-flavor oscillations. This phenomenon can alter the flux of cosmic neutrinos. Considering the current limit on $\mu_{\nu}$ we show that the flux of cosmic neutrinos will reduce by half if they traverse a
few Mpcs through the intergalactic magnetic field, in the range of $\rm \mu G$ to nG.
Furthermore, if the current upper bound is improved by a few orders of magnitude, the effect of $\mu_{\nu}$ can be safely neglected,
even if the neutrinos travel through the size of the visible universe.