A police cordon is in place in Mercury Gardens.
The victim, who is in his 40s, was attacked just after 12.10pm this afternoon in Mercury Gardens.
A Met Police spokesperson said he was found collapsed and taken to hospital, where he is now in a stable condition.
No arrests have been made.
Anyone with information is asked to call police on 101, quoting CAD3088/10JUN, or Crimestoppers on 0800 555 111.
Tags: Romford, Havering