  We analyze various contributions to neutrinoless double beta decay
($0\nu\beta\beta$) in a TeV-scale Left-Right Symmetric Model (LRSM) for type-I
seesaw dominance. We find that the momentum-dependent effects due to $W_L-W_R$
exchange ($\lambda$-diagram) and $W_L-W_R$ mixing ($\eta$-diagram) could give
dominant contributions to the $0\nu\beta\beta$ amplitude in a wide range of the
LRSM parameter space. In particular, for a relatively large $W_L-W_R$ mixing,
the $\eta$-contribution by itself could saturate the current experimental limit
on the $0\nu\beta\beta$ half-life, thereby providing stringent constraints on
the relevant LRSM parameters, complementary to the indirect constraints derived
from lepton flavor violating observables. In a simplified scenario parametrized
by a single light-heavy neutrino mixing, the inclusion of the $\lambda$ and
$\eta$ contributions leads to significantly improved $0\nu\beta\beta$
constraints on the light-heavy neutrino mixing as well as on the $W_L-W_R$
mixing parameters. We also present a concrete TeV-scale LRSM setup, where the
mixing effects are manifestly enhanced, and discuss the interplay between
$0\nu\beta\beta$, lepton flavor violation and electric dipole moment
constraints.
