A census report on employment published on Monday shows that one in five children aged 10 to 17 in Myanmar go to work instead of school.
According to The Occupation and Industry Report - part of Myanmar's 2014 census - about 1.7 million children between the ages of 10 and 17 are working.
"Today, one in five children aged 10-17 are missing out on the education that can help them get good jobs and have employment security when they grow up" Janet E. Jackson, United Nations Population Fund (UNFPA) representative for Myanmar, said in a statement.
The United Nations estimates that many parts of rural Myanmar are mired in poverty and one million people are estimated to be in need of humanitarian aid due to natural disasters and internal conflict which have driven hundreds of thousands from their homes.
The 2014 nationwide census - Myanmar's first in 30 years - was criticised for excluding the country's Muslim Rohingya minorities, who suffer state-sanctioned discrimination.
Most of the 1.1 million Rohingya are stateless and live in apartheid-like conditions in the western state of Rakhine.
The main results of the census were released in May 2015, and showed Myanmar's population stood at 51.4 million - a figure that includes an estimate of the Rohingya population based on pre-census mapping in Rakhine state, according to UNFPA.
The employment data highlighted a gender gap in the labour market, with about half of women aged 15 to 64 working or looking for a job, compared to 85 percent of men.
The report indicated more than half (52 percent) of Myanmar's population is working in agriculture, forestry or fishing sectors.
UNFPA, which assisted the government in carrying out the census, said that these findings can be used to improve agricultural productivity to boost economic growth and farmers' earnings.
The report also showed one in five elderly people aged 65 or older still work, mostly in the physically demanding agriculture, forestry and fishing sectors.
"The data suggest that economic realities oblige many people to continue heavy manual labour into old age to survive. This underlines the need for adequate social services and policies that serve the aged," Jackson said.
Data from other sources show deep poverty in the country.
According to the World Bank, only a third of Myanmar's households have electric light, the infant mortality rate is 62 per 100,000 live births and life expectancy stands at 66.8 years compared to neighbouring Thailand's 74 years.