The star is a patron of children's charity Mending Kids International, a foundation aimed at providing healthcare for ill youngsters in developing nations.
The organisation funded facial surgery for two young girls from Honduras, named Karol and Sara, and Gibson gave them the VIP treatment by taking the pair for a day out at L.A. shopping centre The Grove.
The actor treated the girls to ice cream, before buying them a custom-made doll each.
He tells TMZ.com, "It was really fun spending time with Karol and Sara... They have been through so much and are just so inspirational to everyone who meets them.
"At home, these girls couldn't leave their homes for fear of being tormented. Now, they are walking through one of the most popular tourist areas of Los Angeles."
The Lethal Weapon star will host a special poker event in Hollywood on Saturday (01Dec12) alongside Jodie Foster and Robert Downey, Jr. to raise awareness of the charity.