  We explore possible signals of CPT violation in neutrinos in the complete
three-flavor framework. Employing a systematic expansion in small parameters,
we analytically estimate the CPT violating contributions to the survival
probabilities of $\nu_\mu, \bar{\nu}_\mu, \nu_e$ and $\bar{\nu}_e$. The results
indicate that, in spite of the large number of CPT violating parameters, only a
small number of combinations are relevant for oscillation experiments. We
identify the combinations that can be constrained at the long baseline
experiments, and show that their contribution to the neutrino Hamiltonian can
be bounded to $< 10^{-23}$ GeV, by considering the NOvA experiment for the muon
sector, and neutrino factories for the electron sector.This formalism also
allows us to translate the bounds on the parameters describing non-standard
interactions of neutrinos into the bounds on CPT violating quantities.
