Prayers were held at Nakhoda Mosque, Tipu Sultan Mosque, Kalighat ground, Kidderpore, Rajabazar and Park Circus in the city amidst tight security.
The biggest prayer congregation was at Red Road where around 10,000 people assembled, Kolkata Police officials said.
On the occasion, the Imams of Nakhoda and Tipu Sultan Mosques exhorted the people to uphold the Islamic ideals of love, compassion and unflinching faith.
Later, dressed in traditional attire, people visited homes of their friends and relatives and exchanged gifts.
Chief Minister Mamata Banerjee conveyed her 'Eid Mubarak' wishes to the people of the community.
Leaders of other political parties also greeted them on the occasion.