Ortega, running in his sixth presidential race, is seeking his second consecutive term and third overall even though the Central American nation's Constitution bans presidents from seeking re-election.
"From my point of view, it has been a good government and we hope to keep working in this way," voter Julio Lara explained.
CNN said Ortega has sought to temper his left-wing credentials this time around in order to attract middle-class voters and the business community.
Ortega is also seen as a symbol of continuity in government policy. He first served as president from 1985 to 1990 and then won another term in 2006.
Opponents say Ortega's candidacy is illegal and accuse him of having too much influence over the Supreme Court, which had ruled he could run for president this year.