  The one-loop supersymmetric QCD quantum effects on the width of the
unconventional top quark decay mode $t\rightarrow H^{+}\, b$ are evaluated
within the MSSM. The study of this process is useful to hint at the
supersymmetric nature of the charged Higgs emerging from that decay. Remarkably
enough, recent calculations of supersymmetric corrections to $Z$-boson
observables have shown that the particular conditions by which the decay
$t\rightarrow H^{+}\, b$ becomes competitive with the standard decay
$t\rightarrow W^{+}\,b$ have a chance to be realized in nature. This further
motivates us to focus our attention on the dynamics of $t\rightarrow H^{+}\, b$
as an excellent laboratory to unravel Supersymmetry at the quantum level in
future experiments at Tevatron and at LHC.
