We present a search for tt-bar events with a tau lepton in the
final state. The data sample corresponds to an integrated luminosity of 194
pb-1 collected with the CDF II detector from p anti-p collisions at a center
of mass energy of 1.96 TeV. We observe two events with an expected signal
of 1.0+/-0.2 events and a background of 1.3+/-0.3 events. We determine a
95% confidence level upper limit on r_tau, the ratio of the measured rate of
t --> tau nu q to the expectation, of 5.2.