Abstract
Be stars are early-type Main Sequence objects which have shown at least once some emission in the hydrogen line series. Their most important characteristic is fast rotation, which on average reach ∼ 90% of the critical rate, i.e. Ω/Ω_{c} %∼ 0.90. Since a number of them have masses M > 15 M_⊙, they are ideal targets to study the effects of rotational mixing on the atmospheric CNO abundance and to perform comparisons with the predictions obtained from recent evolutionary models with rotation.
