An Israeli minister said the outcome, which has yet to be confirmed by official results, showed the Lebanese state was indistinguishable from Hezbollah, signalling the risk of Israel hitting Lebanon's government in a future war.
Almost every Lebanese person CNN spoke to before the election said they had little hope in politicians' ability to tackle the country's litany of economic and security woes.
Aoun has since repaired his relations with Syria and created a tactical alliance with Hezbollah, seeing that due to their arms, influence and numerical supremacy, they were the only ones capable of making him president - an ambition he has harbored since the 1980s.
Hezbollah is considered a terrorist organization by the United States, while the European Union differentiates between its political and armed wings.
Sabah Darazi, a 65-year-old retired employee of the Education Ministry, told Xinhua at a polling station in Sidon (Saida), 45 km south of Beirut, that she hoped there will be more women lawmakers in the parliament, citing that Lebanese women are "full of aspiration and wittiness".
Among the main results of the elections is the fixed position of the two Christian parties, the Aounist party and the Lebanese Forces, who have won good blocs, according to their representation.
Hezbollah has grown militarily more powerful since 2012, deploying its fighters to Syria and Iraq where it has fought in support of Iranian allies.
The constitution stipulates that parliament is equally split between Muslims and Christians, whose biggest party, led by President Michel Aoun has been a Hezbollah ally.
While returning many of Lebanon's power brokers to office, the elections also brought in new faces.
Hezbollah had been a dominant player in Lebanon before the election and its improved showing now comes at a time of heightened regional tensions between its patron, Iran, and arch foe, Israel, which in reaction to the result claimed there was no distinction between the party and state.
Official results are expected to be announced by Interior Minister Nouhad Machnouk later on Monday, although no time has been set.
Debt ratings agencies had stressed the importance of Lebanon going ahead with the election after parliament had extended its term several times.
Lebanon's Prime Minister Saad Hariri acknowledged Monday that his parliamentary bloc lost seats in this week's elections, blaming it on a new electoral law and a performance "that wasn't up to the standard".
The next Cabinet, like the outgoing one, will likely be a unity government that includes Hezbollah.
On May 6, the first in nine years parliamentary elections were held.
The Christian and heavily anti-Hezbollah party Lebanese Forces seemed to have doubled their numbers, growing from 8 to 15 seats this election.
The preliminary results show at least one candidate from a civil society list - journalist Paula Yaacoubian - won a seat in the capital Beirut, an area traditionally monopolized by established political parties. It was the first time Lebanon's large expatriate community was allowed to take part in an election. However, the election results coupled with hardening external views about the economic and political state of Lebanon could pose new variables in a country that can ill afford them.
The Lebanon vote is to be followed on May 12 by an Iraqi election that is also set to underline Iran's reach, with one of three pro-Tehran Shi'ite leaders set to become prime minister.
Hariri said confusion over the new electoral process was behind the poor turnout.