Mubarak took 78 percent to 80 percent of Wednesday's polling and opposition candidate Ayman Nour took 12 percent — a respectable showing for a relative unknown and one that could propel him to greater political prominence.
An official on the electoral commission gave the preliminary count to The Associated Press on condition of anonymity because he was not authorized to release the results. A final count was expected Friday.
Despite government promises of a clean race, reports were widespread of pressure and intimidation for voters to support Mubarak. The vote also was marred by low turnout. Nour demanded a rerun.
"After the grave violations that ... influenced the integrity of the election process ... we demanded out of concern national interest that elections be repeated," Nagui al-Ghatrifi, deputy head of Nour's al-Ghad Party, told reporters.
The 77-year-old Mubarak has ruled Egypt for 24 years, re-elected in referendums in which he was the only candidate.
The nation's first open race came amid Washington's push for greater democracy in the Middle East, and while a Mubarak win had been long forecast, the election process was, for many, more important than the results.
Cairo played down reports of irregularities, saying they did not diminish a major step toward reforms.
"There may be some comments, maybe some violations happened, but we have to agree that we're seeing an experience that we can build on for a future that realizes more freedom and more democracy in the Egyptian society," Information Minister Anas al-Fiqi told reporters after polls closed late Wednesday.
In Washington, State Department spokesman Sean McCormack said the Bush administration was following the election closely. He called the vote "a beginning."
"These elections really mark a historic departure for Egypt, in the fact that you have multi-candidate presidential elections. I think it's safe to say that Egyptians have not seen a presidential election like the one they have just seen in their lifetimes," he said.