  We analyze rare K and B decays in the Littlest Higgs (LH) model without
T-parity. We find that the final result for the Z^0-penguin contribution
contains a divergence that is generated by the one-loop radiative corrections
to the currents corresponding to the dynamically broken generators. Including
an estimate of these logarithmically enhanced terms, we calculate the branching
ratios for the decays K^+ -> pi^+ nu bar nu, K_L -> pi^0 nu bar nu, B_{s,d} ->
mu^+ mu^- and B -> X_{s,d} nu bar nu. We find that for the high energy scale
f=O(2-3) TeV, as required by the electroweak precision studies, the enhancement
of all branching ratios amounts to at most 15% over the SM values. On the
technical side we identify a number of errors in the existing Feynman rules in
the LH model without T-parity that could have some impact on other analyses
present in the literature. Calculating penguin and box diagrams in the unitary
gauge, we find divergences in both contributions that are cancelled in the sum
except for the divergence mentioned above.
