Counter-rotating galaxies belong to the class of multi-spin galaxies. They are characterized by the presence of two components that are observed rotating in opposite directions with respect to each other. Before their discovery, counter-rotating galaxies were considered from a theorethical point of view and dismissed as elegant curiosities (see Rubin 1994b, for an historical perspective on the investigation of galactic kinematics). This belief changed when Galletta (1987) measured the kinematics of the ionized-gas and stellar components of the early-type barred galaxy NGC 4564 and showed they are rotating in opposite directions around the same rotation axis. In the same period, the first counter-rotating elliptical (NGC 5898; Bettoni 1984, Bertola & Bettoni 1988) was found in Padua too. As more and more data became available, the presence of counter-rotating components was detected in tens of galaxies along all the Hubble sequence, from ellipticals to irregulars.
Previous reviews about counter-rotation are those by Galletta (1996) and Bertola & Corsini (1999), while Corsini & Bertola (1998) listed all the counter-rotating galaxies known at the time. This paper focuses on the counter-rotation in lenticulars and spirals.