8 May 2012 Last updated at 18:12 BST
Claire Lomas was paralysed from the chest down in a horse-riding accident in 2007, and did the marathon to raise money for charity.
The suit is fitted with motion sensors and allows Claire to walk by detecting shifts in her balance.
As she leans forward to take a step, the suit senses her movement and starts to move her legs for her.
A paralysed woman has completed the London Marathon after 16 days with the help of a 'bionic' suit.