The report by the UN Agency for Human Settlements says that the richest 20% of the population on average earn 20 times more than the poorest 20%.
According to the study, Guatemala is the country with the widest disparity, and Venezuela the most equitable one.
The survey says the region is the world's most urbanised, with eight out of 10 people living in cities.
The report, State of the Cities of Latin America, suggests that by 2050, nearly nine out of 10 Latin Americans will live in cities and its authors suggest Latin American nations use the current period of relative economic stability and slower population growth to make life in the cities more equitable.
"The main challenge is how to combat such huge disparities in the cities," Erik Vittrup of the UN Agency for Human Settlements (UN-Habitat) said.
According to the study, income inequality in Latin America remains extremely high.
"There is a considerable job deficit and a large labour informality affecting mainly the young and women," it says.
The report says that Colombia, Paraguay, Costa Rica, Ecuador, Bolivia, the Dominican Republic, Argentina and Guatemala have all seen an increase in inequality between 1990 and 2009.
But Mr Vittrup said there were some indications of a positive trend.
"We're at the end of an era of urban explosion, with few exceptions.
"We're seeing a reduction in poverty, indigence in urban areas; unemployment is going down," Mr Vittrup said.
He said that, overall, the region was ready for a transition to quality of life, equity and sustainability.

Medway Council is to stop new takeaways opening near secondary schools at lunchtime and near secondaries and primaries after school.
The council said there were currently 179 takeaways within 400m of a school.
The British Retail Consortium (BRC) said it was simplistic to treat all fast food restaurants in the same way.
The restrictions will be used as guidance when the planning committee considers new planning applications.
Councillor Jane Chitty said Medway's public health and children's services were extremely concerned about obesity.
"Allowing the planning committee to take this guidance into account is a positive step," she said.
Local authority health profile figures show 30% of adults in Medway are obese, while the average for England is 24.2% and the wider South East 23.7%.
Among children in Medway, 20% of 10-year-olds are obese.
"To do nothing is not an option," said Councillor David Brake.
"We are already seeing the effect obesity has on our National Health Service and anything we can do to prevent this at an early age is welcome."
A secondary and grammar school that responded to a six-week consultation on the restrictions supported the restrictions.
But the Kent Small Business Federation has called them draconian and said obesity needed to be tackled by changing behaviour.
The BRC said local authorities should encourage companies that wanted to play a positive role in public health and target those that were less responsible.
"There are those that are working positively to cut obesity by removing fats and sugars from food and giving clear calorie labelling on their menu boards to help customers make healthier choices," said director of food and sustainability Andrew Opie.

It was taken to the castle in a procession led by a giant King John figure.
The city holds one of four remaining original copies of the charter, which was signed by King John at Runnymede in 1215.
Schoolchildren who helped make the facsimile also joined the procession.
A trail of 25 decorative sculptures have also been installed in Lincoln - each representing one of the barons who were present at Magna Carta's sealing.
Organiser David Hill said: "We've got a 20m-long parchment - which is a facsimile of the original - and on top of it are words and designs from schoolchildren in the city."
Emma Tatlow, from Visit Lincoln, said the anniversary was helping attract tourists to the city, with more than 70,000 visiting the charter at the Lincoln Castle since April.
Magna Carta outlined basic rights with the principle that no one was above the law, including the king.
It charted the right to a fair trial, and limits on taxation without representation.
It inspired a number of other documents, including the US Constitution and the Universal Declaration of Human Rights.
Only three clauses are still valid: the one guaranteeing the liberties of the English Church; the clause confirming the privileges of the City of London and other towns; and the clause that states that no free man shall be imprisoned without the lawful judgement of his equals.
The British Library has two copies of the 1215 Magna Carta.
Source: The British Library
A study by the United Nations suggests the gap between the rich and the poor in much of Latin America is widening.
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A Kent council has voted to restrict the opening hours of fast food outlets near schools in a bid to tackle rising obesity.
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The 800th anniversary of the Magna Carta has been celebrated in Lincoln with a delivery of a facsimile of the parchment to Lincoln Castle.