Susan Sarandon and Gerard Butler were also among the star volunteers in the country, which was devastated by a massive tremor at the beginning of the year.
The group toured the capital city Port-Au-Prince, while Moore and Sarandon also visited sick kids at the St. Damienis children's hospital.
The Ghost actress was snapped hugging and playing with the youngsters who had been affected by the earthquake - and the experience was emotional for the star after she met one injured little boy.
In a post on her personal Twitter.com page, she wrote, "He was burned and lost three fingers but his joyous spirit was untouched!"
The big-screen stars continued their work on Monday (12Apr10) by volunteering with Penn's Jenkins-Penn Haiti Relief Organization.
They helped move homeless Haitians from a flood-prone camp to a safer area.