There is more poverty in Wales' working households than in those where no one has a job.
The findings, by the Joseph Rowntree Foundation, blame a low pay job market.
Currently 690,000 people in Wales are classed as living in poverty - those who have less than 60 per cent of the average income.
That's almost a quarter of the population here - a higher rate than the other countries in the UK - and worst in rural areas.
Furthermore, 285,000 people - half of those classed as in poverty - are struggling despite having a job.
Dawn Taylor lives near Ruthin in Denbighshire with her partner and nine-year-old son.
She works two hours per day at the local primary school, and her partner is a painter and decorator.
She told ITV News: "It's a struggle every single day. For Christmas I've asked family and friends: 'Just get my son clothes'. I can't afford to go shopping and buy him clothes."
She added: "We're too honest to say: 'Forget working - we'll go on benefits'. We want to work. But we're struggling."
Andy Fox is the General Manager at Cedar Tree Farm, a new restaurant opening in Cardiff.
He is looking to recruit 100 workers and says there was a 'fantastic response' from jobseekers at the jobs fair, particularly from people looking for extra work to boost their income.
"A lot of people come in looking for part-time work," he said. "Obviously people have other jobs; they want a bit of extra money."
David Cramb, from Barry, was one of more than 3,000 people at a jobs fair in Cardiff yesterday.
He is a full-time van driver, but also does bar work to earn more money.
He says he has worked 22 hours a day at times, but added: "It does affect the quality of your life - come the weekend you've got no energy to do anything."
David is looking for more part-time work, as money is tight.
"We're surviving," he said. "It's paying the bills, buying food, and that's about all we can cover at the moment."
A Department for Work and Pensions spokesperson has responded to criticism that it is not doing enough to tackle the issue of low pay and low working hours, saying it is 'committed to making work pay'.
The Deputy Minister for Tackling Poverty, Vaughan Gething, says the "sluggish" economic recovery has meant there are many people in Wales who are forced to work part-time, or take on lower wages to have some sort of work.
He told our reporter Tom Sheldrick that the Welsh Government's Tackling Poverty Action Plan - relaunched in July - is "a recognition that we need to create, not just more work, but better work."
One of the authors of today's report - Monitoring Poverty and Social Exclusion in Wales 2013 - says politicians in Westminster and Wales need to focus on improving workers' pay and hours, as well as job creation.
Peter Kenway, the Director of the New Policy Institute, says "the politicians have been very alert to the idea that people aren't working enough. They have had nothing to say about pay - and we're saying they need to do something about that."
He advocates the introduction of a Living Wage across Wales. The idea is promoted by the Living Wage Foundation, and based on the amount an individual needs to earn to cover the basic costs of living.
It is set at £7.45 per hour, and higher for London. Cardiff is one of several big local authorities in the UK to adopt it.
The report found 690,000 people in Wales are in poverty - nearly a quarter of the population of just over 3 million.
It reveals a much higher number of families living in poverty when workers are part-time, and earning less than the Living Wage.
- 690,000 people in Wales were living in poverty in the three years to 2011/12 - a higher poverty rate than in England and Scotland
- 51 per cent of those in poverty are from working families, compared to jobless families
- 29 per cent of families working part-time live in poverty, compared to 7 per cent for full-time working families
- 23 per cent of workers earning less than the Living Wage of £7.45 per hour live in poverty, compared to 3 per cent of those earning more
A household is considered to be in poverty if its income (after tax and adjusted for household size) is below 60 per cent of the UK median for the year.
The report - published once every two years - was prepared by a team at the think tank the New Policy Institute, for the Joseph Rowntree Foundation.
There has been a "shocking rise" in the number of people who are in work, but living below the poverty line, in Wales.
That is the warning from an influential report - Monitoring Poverty and Social Exclusion in Wales 2013 - published today by the Joseph Rowntree Foundation.
There are now marginally more working families in Wales living in poverty, compared to jobless families.
It blames the situation on low pay and underemployment - with many people not able to work the number of hours they would like to.
The report calls on the UK and Welsh governments to focus on increasing pay and hours - as well as job creation.