The agency was added to the Barnardo's roster 18 months ago and had since taken on the bulk of its direct business from EHS Brann.
Steve Aldridge, the creative partner at Andrews Aldridge, said: "To create great work, you need to work together with a shared vision, which we don't have. We wish it every success in the future."
A spokeswoman for Barnardo's said: "After a successful 18-month relationship during which Andrews Aldridge and Barnardo's produced some very effective DM campaigns, it has been agreed that the two organisations will not be working on any new projects. Barnardo's would like to thank Andrews Aldridge for its hard work."
During its time on the account, Andrews Aldridge created TV and direct mail work. This included the charity's first DRTV work in 2003.