The review began in February with seven agencies making it on to the longlist before it was reduced to a final two.
Adam & Eve will now create a multimedia national mobilisation campaign designed to increase donations to the charity while building the brand.
Save the Children has also recently appointed a media agency in preparation for the campaign.
In February, John Ayling & Associates, working together with agenda21, beat MediaCom and the7stars to the business. The incumbent on the account was Carat.
There was no incumbent on the above-the-line business.
Save the Children has recently used agencies on a project-by-project basis. Its most recent partner was Wieden & Kennedy, which has not worked on the account since early 2009.
The charity's last heavyweight campaign broke in February this year and was created by Touch DDB, which handles its digital and below-the-line accounts.
The campaign consisted of four virals that charted the most pivotal periods in Save the Children's history: 1919, when it was launched; World War II; the 70s, when it became a household name; and the 2004 tsunami in Asia.