  Experimental progresses in the miniaturisation of electronic devices have
made routinely available in the laboratory small electronic systems, on the
micron or sub-micron scale, which at low temperature are sufficiently well
isolated from their environment to be considered as fully coherent. Some of
their most important properties are dominated by the interaction between
electrons. Understanding their behaviour therefore requires a description of
the interplay between interference effects and interactions.
  The goal of this review is to address this relatively broad issue, and more
specifically to address it from the perspective of the quantum chaos community.
I will therefore present some of the concepts developed in the field of quantum
chaos which have some application to study many-body effects in mesoscopic and
nanoscopic systems. Their implementation is illustrated on a few examples of
experimental relevance such as persistent currents, mesoscopic fluctuations of
Kondo properties or Coulomb blockade. I will furthermore try to bring out, from
the various physical illustrations, some of the specific advantages on more
general grounds of the quantum chaos based approach.

Mesoscale and Nanoscale Physics