A man has been rushed to hospital with minor injuries after being hit by a falling concrete slab in Auckland's city centre.

The falling slab of concrete was 2 x 2 metres in size, and fell about a metre onto the road below a construction site at the corner of Centre St and Sales St.

St John Ambulance staff and fire crews attended the incident on a Macrennie construction site shortly after 2pm this afternoon.

Company spokesman Steve Fowler said Worksafe had been advised, and the company was also conducting its own internal investigation.

"We're seeing if it was an operator issue - a human error", he said.

The falling slab of concrete fell about a metre onto the road below, hitting the man and causing minor injuries.

The patient is now in a stable condition in Auckland Hospital.

A Worksafe spokesperson said they had been notified of the incident, and the department is making initial inquiries.