  It is argued that apart from the well known dependence of the Am phenomenon
on the mass, age (effective temperature, gravity) and rotation there is also a
complex dependence on the orbital parameters in binary systems. This is why the
generally accepted scenario in which the Am star rotation plays a unique role
needs to be revisited, the strong correlations between the rotation, orbital
period and eccentricity need to be properly addressed and tidal effects taken
into account. Recent observations of Am stars in binary systems are reviewed.
