The news comes just 11 months after Fallon poached Silburn from TBWA\London.
The Fallon Worldwide chairman, Pat Fallon, appointed him to replace David Lubars, who left to join BBDO.
In a terse e-mail to the whole company, followed by a press statement, Pat Fallon said: "Paul is a brilliant creative talent and a great guy, but I am not satisfied with our progress. I needed to make a change and that change called for decisiveness."
Silburn said: "Professionally, I'm disappointed Pat has pulled the plug after only 11 months. Personally, I feel really happy to be going home.
I feel like Terry Waite. Pat said he needed change. I agree that Fallon needs change. Ironically, trying to implement change is kind of what got me fired."
The twin firings come on the back of a series of losses for the Minneapolis agency, with BMW, Dyson and Lee Jeans all moving to other agencies.
Fallon was also forced to close its New York office in July 2005 after the resignations of its president, Anne Bologna, and its executive creative director, Ari Merkin. It lost the Virgin Mobile account to Mother New York in the process.