  Rare heavy flavor decays are an ideal place to search for the effects of
potential new particles that modify the decay rates or the Lorentz structure of
the decay vertices. The LHCb experiment, a dedicated heavy flavour experiment
at the LHC at CERN. It has recorded the worlds largest sample of heavy meson
and lepton decays. The status of the rare decay analyses with 1\,fb$^{-1}$ of
$\sqrt s = 7\,$TeV and 1.1\,fb$^{-1}$ of $\sqrt s = 8\,$TeV of $pp$--collisions
collected by the LHCb experiment in 2011 and 2012 is reviewed. The worlds most
precise measurements of the angular structure of $B^0\rightarrow K^{*0} \mu^+
\mu^-$ and $B^+\rightarrow K^{+} \mu^+ \mu^-$ decays is discussed, as well as
the isospin asymmetry measurement in $B\rightarrow K^{(*)} \mu^+ \mu^-}$
decays. The first evidence for the very rare decay $B^0_s \rightarrow \mu^+
\mu^-$ is presented together with the most stringent upper exclusion limits on
the branching fraction of decays of $B^0$, $D^0$ and $K^0_s$ mesons into two
muons. This note finishes with the discussion of searches for lepton number and
lepton flavor violating $\tau$ decays.
