The appointment, worth £3 million, followed a competitive pitch against a group of agencies. These included the incumbent, Superhero, which is being retained by Emap Consumer Media to work on various projects across the group's portfolio of men's magazines.
The hiring comes two weeks after the title was revamped under its new editor-in-chief, Anthony Noguera.
Nial Ferguson, Emap's head of marketing for men's magazines, said: "Zoo is moving to the next stage of its development and is broadening its appeal to an even wider group of readers. The appointment of BMB reflects this.
"While the title will remain sexy, it will evolve, becoming even funnier and smarter. BMB and Zoo feel like an exciting combination."
The BMB founding partner Andrew McGuinness commented: "We're delighted to have won such a prestigious account. This is a great brief, and our challenge is to help Zoo to the next level."
Launched in March last year, Zoo is the fastest-growing men's magazine in the UK. In the August Audit Bureau of Circulations figures, the title posted audited sales of 260,712 copies, which equated to growth of 30 per cent year on year.