The Islamist Abdelmoneim Abul Fotouh suffered a concussion after three men armed with rifles assaulted him on Cairo's ring road and stole his car, his campaign manager Ali al-Bahnasawy told reporters.
His campaign said in a statement that Abul Fotouh was wounded by blows to the head with a rifle butt as he tried to defend his driver. The driver was also wounded, a police official said without detailing his injuries.
Abul Fotouh was returning from a campaign event north of the capital when the apparent robbery happened.
Abul Fotouh, a former senior member of the powerful Muslim Brotherhood movement, is considered one of the more popular candidates in the election, which is set to take place by the end of June.