In its study of extreme poverty, the Bank said Sub-Saharan Africa accounted for more than a third of the world's extreme poor.
On the brighter side, the report said those living on less than $1.25 a day in the developing world fell sharply in the past three decades to 21 percent in 2010 from about 50 percent in 1981. The improvement has come despite a 59 percent increase in the population during the same period in the developing world.
"We have made remarkable progress in reducing the number of people living under $1.25 a day in the developing world, but the fact that there are still 1.2 billion people in extreme poverty is a stain on our collective conscience," said World Bank Group President Jim Yong Kim.
He asked the international community to take its fight against poverty to the next level so extreme poverty can be ended by 2030.
The report said Sub-Saharan Africa is the only region in the world where the number of the poor has risen steadily between 1981 and 2010 to 414 million from 205 million three decades ago.
In 2010, the average daily income of the extremely poor in the developing world was 87 cents per capita, up from 74 cents in 1981 (in 2005 Purchasing Power Parity dollars). However, in sub-Saharan Africa, the average income of the extremely poor has remained essentially flat at about half the $1.25 line, the report said.
"We have made strides in cutting down poverty, but with nearly one-fifth of the world population still below the poverty line, not enough," said Kaushik Basu, the Bank's chief economist.