More than 56 million people have been lifted out of poverty in Latin America and the Caribbean in recent years, according to the United Nations Development Programme (UNDP).
A new UNDP report says poverty levels in the period from 2000-2012 fell from 41.7% to 25.3% of the population.
But despite the progress, it warned that some 200m people, or 37.8% of the population, remained vulnerable.
The UNDP has called for more investment in social protection programmes.
It calculates poverty as living with less than $4 a day.
"In Latin America and the Caribbean, poverty has been reduced by almost half in the last decade, and the middle class rose from 22% of the population in 2000 to 34% in 2012," UNDP Director for Latin America and the Caribbean Jessica Faieta said.
"Despite these achievements, a very high share of the population is living in constant uncertainty.
"They are neither classified as living in poverty, nor have they gained access to a stable middle class status," she said.
The people living on between $4 and $10 a day went up by 3.4% between 2000 and 2012.