Top quark production offers the unique opportunity to search for a charged Higgs;boson (H+/-), as the contribution from t-->H+ b-->tau(+) nu b can be large in extensions of the standard model. We use results from a search for top quark pair production by the Collider Detector at Fermilab (CDF) in the e tau + E-T + jets and mu tau + E-T + jets signatures to set an upper limit on the branching ratio of B(t-->H+ b) in 106 pb(-1) of data. The upper limit is in the range 0.5 to 0.6 at 95% C.L. for H+ masses in the range 60 to 160 GeV, assuming the branching ratio for H+-->tau nu is 100%. The tau lepton is detected through its 1-prong and 3-prong hadronic decays. RI Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Nomerotski, Andrei/A-5169-2010; Prokoshin, Fedor/E-2795-2012; Chiarelli, Giorgio/E-8953-2012; Azzi, Patrizia/H-5404-2012