The Portugal international has signed a contract until June 2015 after being released from his contract with the Liga club.
Nelson joined Betis from Benfica in 2008, though spent the 2010-11 season on loan with Osasuna.
Palermo have announced that Nelson will be presented to the press on Tuesday, along with striker Mauro Boselli who has joined the club on loan from Wigan.
The Rosanero have also confirmed that goalkeeper Samir Ujkani will spend the remainder of the season on loan at Chievo Verona.
- Sports & Recreation