The Iranian president touched down in the Italian capital Rome on Monday.
He is accompanied by over 100 businessmen, ministers and officials who are expected to help him clinch deals worth billions in trade and investment.
The agreements are expected to be topped by a major order for new Airbus planes. Iranian National carrier Iran Air said on Sunday it would be buying 114 Airbus planes to modernize its fleet
Following his arrival in Rome, Rouhani on Monday was ushered away for a working lunch with Italian President Sergio Mattarella, the first appointment in a five-day trip.
Rouhani, a former academic and diplomat, was scheduled to meet Italian Prime Minister Matteo Renzi on Monday evening.
He will be received by Pope Francis on Tuesday and by French President Francois Hollande on Wednesday
The fight against the Daesh militant group and the ongoing crisis in Syria are expected to feature highly in diplomatic contacts during the visit.
Rouhani told reporters before his departure on Monday from Mehrabad Airport that Tehran would seek to continue to maintain good bilateral ties with the European nations. "We have had friendly relations with Italy and France in the past and we want to continue our good relations with them."
Iranian officials have noted that "important contracts" were in the works with French car makers Peugeot and Renault.
The trip follows the implementation of the nuclear agreement between Tehran and the P5+1 group of countries as well as the lifting of the sanctions against Iran.
Iran and the P5+1 group reached the agreement, known as the Joint Comprehensive Plan of Action (JCPOA), in July 2015.
On January 16, the accord came into force known as the “Implementation Day.”
It is notable that Imam Khomeini, founder of the Islamic Republic used to highlight through his speeches and messages the need for maintaining good bilateral ties with all nations.
Iran made a great amount of progress in all perspectives after the victory of the Islamic Revolution under matchless leadership of Imam Khomeini.