The number of people living in cities without access to civic amenities has increased by 60.43 percent in the last 17 years.
According to the latest census on slum dwellers and floating population conducted by the Bangladesh Bureau of Statistics (BBS) last year, 2.23 million people live in slums across the country.
Of them, 1.14 million are males, 1.09 million females, and 1,852 transgender people.
The results of the census, third of its kind in the country, were published on Monday.
The second census, conduced in 1997, had found 1.39 million people living in slums.
Most of those who relocate to cities to earn their livelihood after losing their land and houses to river erosion or other reasons take shelter in unhealthy and densely populated slums.
The census Project Director Mohammad Zafar Ahmed Khan said they had counted as slum dwellers those who live in makeshift or dilapidated houses on government or semi-government land.
Bangladesh Bureau of Statistics Director General Mohammad Abdul Wazed, Secretary Kaniz Fatima and other officials were present at the report-release function.
The bureau did the census from Apr 25 to May 2 last year. It had carried out the first census on shanty dwellers in 1985.
The latest census report says 1.06 million people live in slums in Dhaka division, followed by the Chittagong, Khulna and Rajshahi divisions with 635,916, 172,219 and 120,036 slum dwellers respectively.
The slum population is 118,628 in Rangpur, 91,630 in Sylhet and 49,401 in Barisal divisions, according to the report.
It says 27.25 percent slum dwellers own their houses, while 64.87 percent live in rented tenements and 6.99 without paying any rent.
The census found that 89.65 percent of the shanty people had access to electricity while 9.7 percent used kerosene lamps and 0.33 percent solar power.
The report says 52.48 percent of the slum people use tube-well water and 45.21 percent depend on piped water provided by the authorities.
It says 42.19 percent slum dwellers use unhygienic toilets and 26.25 sanitary latrines.
According to the report, 50.96 percent of the shanty people relocate to cities in search of jobs, 28.76 percent due to poverty and 7.04 percent after losing their lands and houses to river erosion.
It says 33.26 percent slum people are literate.
According to the report, 84.07 percent are landless and 15.93 percent own lands.
Of the slum dwellers, 92.66 percent are Muslims and 6.73 percent Hindus.
According to the report, 17.88 percent of the shanty people are housewives, 13.33 percent students, 13.18 percent garment factory workers, 7.58 percent traders, 6.92 percent rickshaw-pullers, 6.71 percent job holders and 6.41 percent domestic helps.