The Brazil international has previously been linked with a move to Juventus, but the Rossoneri have now shown an interest in signing the defenderhere.
Dede could be on his way out of Vasco da Gama in the summer transfer window as AC Milan have shown an interest in luring him to Serie A ahead of the 2012-13 campaign, Corriere dello Sport reports.
The Rossoneri are in the market for defensive reinforcements due to the ongoing uncertainty about the future of Thiago Silva, and they see the highly-rated 23-year-old Dede as a good replacement in case the former leaves the San Siro side.
Milan are determined to hold on to Thiago Silva, but they could be tempted to cash in on the centre-back if a big-money offer comes in this summer.
Dede joined Vasco from Volta Redonda in 2009, and has since developed into a key player at the Gigante da Colina.
He has previously been linked with a move to Juevntus, but Massimiliano Allegri's side now appear to be sitting in pole position to sign the centre-back instead.
The Brazil international has a contract with Vasco until December 2014, and an offer in the region of €7-10 million (£5-8m) could be needed to lure him away from his current employers.