Stars such as James Nesbitt, David Beckham, Ewan McGregor and Cat Deeley gave their support to charity to mark the 20th anniversary of a major agreement on children's rights.
They chose photographs from their visits to poor countries for a Unicef 'photo pledge' campaign, in a bid to raise awareness.
Beckham picked an image from his visit to Sierra Leone which shows him meeting a mother with a malnourished child at a feeding centre to illustrate his belief in the child's right to good health.
The campaign sees Unicef team up with the World Photography Organisation to highlight the 20th anniversary of the United Nations Convention on the Rights of the Child.
Organisers hope to encourage people around the world to pledge a photo and a written pledge portraying one of the five fundamental rights from the convention: The right to survival, education, health, protection from harm and to be heard.
McGregor's chosen image featured youngsters at a childcare centre in Malawi.
He said: "They are flat out asleep having an afternoon nap in a centre that's been set up to provide them with a meal, toys and childcare and a time and place to be children.
"It looks basic. It is. But the centre is helping give these children their rights - care, support, education and more. I pledge my absolute support for children's rights. I hope you'll do the same."
Beckham said of his image: "Every child has the right to be healthy. We can't turn a blind eye to the tens of thousands of young children who die every day in the developing world, mostly from causes that are preventable."
Others who have chosen images include presenter Deeley, jazz act Jamie Cullum, actor James Nesbitt and Jemima Khan.
The UNCRC has been signed by almost all countries making it the most widely ratified human rights agreement in the world.
Despite improvements to reducing child mortality there are still major challenges such as the 150 million children, aged between five and 14, who are involved in child labour.
© Press Association