  We present an implementation of the production of three jets at NLO plus
parton-shower effects in the POWHEG BOX. Using the recently introduced MiNLO
procedure for setting the renormalization and factorization scales, we are able
to obtain a generator that is also well behaved when the third jet becomes
unresolved. We compare key distributions computed at the NLO level, at the
level of the POWHEG hard emission and after full shower by PYTHIA, Pythia8 and
HERWIG6. We also compare our three-jet generator with the already available
dijet POWHEG generator.
