Sydney's much-maligned monorail will loop around the city for the final time tonight after nearly 25 years of service.

The New South Wales Government is tearing down the track to build a new convention centre.

Sydney's Lord Mayor says the demise of the monorail, which has eight stations along the 3.6 kilometres of track, will eventually lead to improved public transport in the city.

Clover Moore says the monorail was never efficient.

"When the monorail comes down and the George Street light rail progresses, that will be moving 8,000 people an hour," she said.

"People will be able to get out at Central [Station] and then move easily through the city.

"That will be the beginning, I hope, of a light rail network and that'd be part of the integrated transport system that Sydney desperately needs."

The Sydney monorail was controversial even before it opened in 1988.

It was opposed by many who claimed a light rail service would be cheaper and less ugly.

Frank Sartor was a city councillor at the time and says he hated it then, and still hates it now.

"It's aesthetic mainly - I mean, it interrupts the streetscapes of Sydney," he said.

"It didn't serve particularly well as a transport system, although some people that live locally, they like it and it works for them."

The monorail's last journey will be at 9:30pm AEST this evening.