The 'Kiss You' hitmakers jetted out to the continent last Saturday and began their week visiting local people in the deprived area of Accra, Ghana, for the British charity ahead of its Red Nose Day 2013 telethon.
After spending time entertaining children in a school and raising donations for the poverty-stricken town, the boys - Niall Horan, Harry Styles, Liam Layne, Zayn Malik and Louis Tomlinson - described it as "the best" and most "amazing" experience they have ever had and have urged people to help the cause.
Niall, 19, posted on his Twitter account: "Just arrived back from Accra, Ghana! Best experience ever! This @rednoseday please get involved!
"I've seen the slums right in front of me! This is no joke! They really need your help! Poverty is real !
"Massive thanks to @rednoseday for taking us to Ghana! It was incredible! real eye opener! We take so much for granted over here ! (sic)"
Harry, 18, also shared his feelings about the trip, tweeting shortly after: "Today was the most amazing day I've had so far.. In my life ever. (sic)"
Louis, 21, wrote: "So honoured to be a part of @rednoseday . Met some beautiful people over in Ghana. Please donate big this year!(sic)"
The pop stars are believed to have headed over to Cape Town, South Africa, following their visit to Ghana to shoot a music video for the charity.
Comic Relief's Red Nose Day takes place on March 15 and includes various celebrities taking part to help "transform the lives of countless people, both here at home in the UK and across Africa". It airs on British TV channel BBC One.