  We study the decay B -> X_s gamma within the framework of the minimal 331
model, taking into account both new experimental and theoretical developments
that allow us to update and improve on an existing ten year old analysis. In
contrast to several other flavor changing observables that are modified already
at tree level from a new Z' gauge boson, we have only one loop contributions in
this case. Nevertheless, these are interesting, as they may be enhanced and can
shed light on the charged gauge boson and Higgs sector of the model.
Numerically, we find that the Higgs sector, which is well approximated by a 2
Higgs doublet model (2HDM), dominates, since the gauge contributions are
already very strongly constrained. With respect to B -> X_s gamma, the signal
of the minimal 331 model is therefore nearly identical to the 2HDM one, which
allows us to obtain a lower bound on the charged Higgs mass. Further, we
observe, in analogy to the 2HDM model, that the branching fraction can be
rather strongly increased for small values of tan beta. Also, we find that B ->
X_s gamma has no impact on the bounds obtained on rare K and B decays in an
earlier analysis.
