  Blue Straggler stars are present in all the properly observed Globular
Clusters. They mimic a rejuvenated stellar population and their existence has
been a puzzle for many years. We performed an extensive spectroscopic survey of
the surface abundances and the rotational velocities of Blue Straggler stars in
different Globular Clusters, by using the high-resolution spectrograph
FLAMES@VLT in the UVES+GIRAFFE combined mode. In this contribution we show our
main results obtained for M4, {\omega} Centauri and M30.
