In October 2008, Gomez was named UNICEF's spokesperson for the Trick-or-Treat for UNICEF campaign, which encouraged children to raise money on Halloween to help children around the world.[36] She said that she was "extremely excited" to "encourage other kids to make a difference in the world."[36]
In August 2009, at 17, Gomez became the youngest UNICEF ambassador ever, passing fellow songstress Hayley Westenra. In her first official field mission, Gomez traveled to Ghana on September 4, 2009 for a week to witness first-hand the stark conditions of vulnerable children that lack vital necessities including clean water, nourishment, education and healthcare.[37][38] Gomez said during a interview with Associated Press that she wanted to use her star power to bring awareness to Ghana: “That’s why I feel very honored to have a voice that kids listen to and take into consideration [...] I had people on my tour asking me where IS Ghana, and they Googled it […] and because I went there, they now know where Ghana is. So it’s pretty incredible.”[38][39] Gomez said of her role as ambassador that: "Every day 25,000 children die from preventable causes. I stand with UNICEF in the belief that we can change that number from 25,000 to zero. I know we can achieve this because every moment, UNICEF is on the ground providing children with the lifesaving assistance needed to ensure zero becomes a reality."[37]
Gomez was named spokesperson for UNICEF's 2009 Trick-or-Treat campaign, for the second year in a row.[40] Gomez, whom raised over $700,000 for the charity in 2008, stated that she hopes to be able to raise 1 million dollars in 2009.[38] Gomez participated in a celebrity auction[41] and hosted a live web cast series on Facebook in support of the Trick-or-Treat for UNICEF campaign. [42] Gomez will return as the UNICEF spokesperson for the 60th anniversary of Trick-or-Treat for UNICEF campaign in 2010.[43]