  The unification of gauge interactions in the context of Adjoint SU(5) and its
phenomenological consequences are investigated. We show the allowed mass
spectrum of the theory which is compatible with proton decay, and discuss the
possibility to have a cold dark matter candidate. Due to the upper bounds on
the proton decay partial lifetimes, tau (p --> K^+ nubar) < 9.3 10^{36} years
and tau(p --> pi^+ nubar) < 3.0 10^{35} years, the theory could be tested at
future proton decay experiments. The theory predicts also light scalar color
octets which could be produced at the Large Hadron Collider.
