  During the last decade and a half, the new generation spectropolarimeter
Narval at Pic du Midi, France allowed the study of weak magnetic fields in cool
giant stars that are fairly evolved after main sequence. We present a short
summary on the recent knowledge on the magnetic fields and activity in giants
situated in the upper right part of the Hertzsprung-Russel (H-R) diagram and
discuss on the possible mechanisms for magnetic field generation in the
asymptotic giants branch (AGB) and post-AGB stars.
