We study the conditions under which flavor violation arises in scalar-fermion interactions, as a result of the mixing phenomena between the standard model and exotic fermions. Phenomenological consequences are discussed within the specific context of a left-right model where these additional fermions have mirror properties under the new ${\mathrm{SU}(2)}_{R}$ gauge group. Bounds on the parameters of the model are obtained from LFV processes; these results are then used to study the LFV Higgs decays $(\stackrel{\ensuremath{\rightarrow}}{H}\ensuremath{\tau}{l}_{j},$ ${l}_{j}=e,\ensuremath{\mu}),$ which reach branching ratios that could be detected at future colliders.