We present results of a search for the top quark decaying to a charged Higgs boson ($H^+$) in $p\bar{p}$ collisions at $\sqrt{s}=1.8$ TeV at the Fermilab Tevatron. Assuming that $H^+ \rightarrow\tau\nu_\tau$ is the dominant $H^+$ decay mode, we exclude regions of the ($m_{H^+}$,m_t) plane for values of the branching ratio $B(H^+ \rightarrow\tau\nu_\tau)=0.5,0.75, and 1.0$. We interpret the results in terms of the parameter tan$\beta$ in the two-Higgs-doublet model.