  I discuss the issue of quark-hadron duality in the system of heavy-light
quark mesons. As an example, I consider a correlator of two currents comprising
heavy quark operators, and I compare the OPE expression with the result
obtained by a complete insertion of hadronic states. After a smearing
procedure, OPE and hadronic spectral functions agree with each other. However,
the local behaviour of the two functions is different, and the difference
manifests itself in a term which is absent in the OPE.
