Hundreds of thousands have gathered in and around the Ijtema grounds to attend the prayer, which will be conducted by Indian cleric Mawlana Mohammad Saad.
Traffic between the Bhogra Bypass intersection and Shahjalal International Airport on the Dhaka-Mymensingh highway had remained suspended since Saturday midnight.
Devotees were seen walking down to the already overflowing Ijtema ground since early on Sunday.
Police said that apart from Muslims from 17 Bangladesh districts, another 6,360 from 95 countries across the world have joined the second phase of the Ijtema.
Gazipur's Superintendent of Police Harun Ur Rashid said they have intensified security measures, which include deploying a few thousand policemen in and around the Ijtema venue.
Railway authorities have arranged 14 special train services to accommodate devotees returning home after the final prayers.
The first phase of the Ijtema started on Jan 13 and ended on Jan 15, where devotees from 17 other districts, including Dhaka took part.
The Bishwa Ijtema, the second largest Muslim congregation after the Hajj, was first organised at Dhaka's Kakrail Mosque in 1946.
Two years later, it was held at Chittagong's Haji camp followed by one at Narayanganj’s Siddhirganj in 1958.
As the number of participants increased, the congregation was eventually moved to the banks of Turag in Gazipur.
Later, 160 acres of land was acquired and developed as a permanent Ijtema ground.
Since 2011, it's being held in two phases, to avoid overcrowding.
But last year, the organisers planned a four-phase Ijtema that will be spread over two years to enable Muslims from the country’s 64 districts to join in.