Although he started his career as a striker with Ghazl El Mahalla, he played as a right-sided defender after joining ENPPI. He was selected by the Egyptian national team's manager, Hassan Shehata, for his first international appearance in 2007.
For a long time, Elmohamady attracted the attention of several European clubs. However, ENPPI was reluctant to allow him to move to any of them. In summer 2007, ENPPI turned down an offer from Hertha BSC, because the German side failed to meet the Egyptian club's financial demands. The player refused another bid from Rapid București of Romania in 2007.
Elmohamady played several times for U21 Egypt national football team, and was a participant in the 2007 African Youth Championship which was held in Republic of the Congo – he was the rising star of the Egyptian team and one of the stars of the tournament despite his playing out of position as he played forward.
He made his senior international debut in August 2007 at the age of 20, in a friendly against Ivory Coast in Paris and has played eight of Egypt's last nine matches before ACN 2008. He's included in the final squad of Egypt which competed in ACN 2008 in Ghana and grabbed the cup, where he played a role as a substitute. Since then, he reserved his place in the starting line up as a Right-back or Winger. He started all Egypt's six matches in the second round of FIFA World Cup 2010 Qualifiers.