An early tour of Cairo polling stations suggested authorities would again struggle to get people to cast their ballots.
After months of adulation by the media encouraged by his supporters in government, the security services and business, many Egyptians were shocked when the election failed to produce the mass support predicted by Sisi himself.
For Sisi, locked in a battle with the Muslim Brotherhood after toppling Islamist president Mohamed Mursi last year, the stakes are high.
Poor backing in the election in his deeply polarised country would mean Sisi's legitimacy as head of state of the Arab world's most popular nation would be harmed at home, in the Middle East and in the wider world.