Save the Children Scotland say the number of children living below the breadline remains "unacceptably high" despite a steep fall in the latest figures.
Official statistics show that more than one in five youngsters - 21 per cent - were living in relative poverty in 2010-11. The total figure for Scotland is 220,000, 30,000 fewer than the year before.
Among the whole population 15 per cent of people (780,000) were classed as living in poverty, though the total rises to 910,000 if housing costs are accounted for. The number of pensioners in relative poverty was unchanged at 160,000.
Douglas Hamilton, head of Save the Children's in Scotland, warned that the fall was likely to be reversed as welfare cuts start to filter through.
He said: "The numbers are still unacceptably high and there is much more work to be done."
"It does show that it is possible to tackle child poverty when the political will is there and the right actions are taken. However, spending cuts and high unemployment means that such progress will be shortlived.
"The number of children growing up cold and hungry because their parents can't afford basic essentials is set to rise in Scotland over the next eight years, wiping out all the progress that has been made. The UK Government must stop these spending cuts which are pushing families deeper into poverty and do much more to ensure parents can get decent and well-paid jobs.
"In Scotland, it is vital that the Child Poverty Strategy is followed through to make sure that everything that can be done is being done within our own devolved powers."
John Dickie, head of the Child Poverty Action Group (CPAG) in Scotland, said the "unprecedented progress" made in tackling child poverty is "now under massive threat from UK Government policies".
He said: "The coalition must now rise to the challenge, rethink their child poverty strategy and reject attempts to move the goalposts and redefine, rather than lift children out of poverty.