The inauguration ceremony opened at the Parliament building in Tehran on Saturday.
The ceremony took place in the presence of the country’s high-ranking officials as well as leaders and senior politicians from around the world.
The delegates from more than 100 countries, including several heads of state, attended the ceremony.
Rouhani took the oath of office and proceeded to his speech.
Addressing the ceremony, Rouhani thanked world leaders and dignitaries for taking part in the swearing-in ceremony.
He said the Iranian nation has made great sacrifices in the path of safeguarding freedom and the rule of law, adding that Iranians have put their trust in the Islamic establishment.
He vowed to follow the Iranian nation’s demands and emphasized that his government is ready to defend the country’s national interests.
In May, Rouhani won re-election in a landslide victory after securing 57 percent of the votes.
On Thursday, Leader of the Islamic Revolution Ayatollah Seyyed Ali Khamenei formally endorsed Rouhani as president.
This process, called Tanfiz (validation), the Leader affirms the outcome of the presidential election.
Under Iran’s election law, the president-elect is required to gain the Leader’s official approval before being sworn in before the Parliament (Majlis).