The NSPCC held the fundraiser in glorious sunshine on Sunday.
Not that the weather mattered to those taking part - their climb was firmly indoors, tackling the building's 1,308 steps.
And the fastest time was made by seasoned amateur runner Rich Sirrs, with an impressive four minutes, 23 seconds.
Formally 30 St Mary Axe, the building is known for its familiar shape and hundreds of people took part in the event.
And celebrities through themselves into the challenge too. 'Countdown' presenter Rachel Riley completed it in just under nine minutes.