Elmohamady seals Sunderland switch
The 23-year-old right-back, who can also play on the wing, joined Sunderland on a season-long loan deal in July 2010 from Egyptian side ENPPI and made 38 appearances in his debut campaign.
The loan deal allowed Sunderland to make the move permanent for an undisclosed pre-arranged fee and he has signed a contract until 2014.
"Ahmed has done well in his first season with the club and has shown plenty of potential," manager Steve Bruce said on the club website.
"We look forward to helping him grow as a player and I think there is much more to come from him."
Elmohamady is Bruce's first foray into the transfer market after the club agreed to sell midfielder Jordan Henderson to Liverpool in deal British media reported would be up to 20 million pounds.
Some of that money could be heading to Manchester United as Bruce has been tipped to raid his former club for defenders Wes Brown, John O'Shea and midfielder Darron Gibson.