  We report a search for CP violation in the decay \tau- -> \pi - \K^0_S (>= 0
\pi 0) \nu_\tau\ using a dataset of 437 million \tau\ lepton pairs,
corresponding to an integrated luminosity of 476 fb^{-1}, collected with the
BABAR detector at the PEP-II asymmetric energy e+e- storage rings. The
CP-violating decay-rate asymmetry is determined to be (-0.45 +/- 0.24 +/-
0.11)%, approximately three standard deviations from the Standard Model
prediction of (0.33 +/- 0.01)%.
