Nightclub owners and staff say jobs will be lost as a result of new laws aimed at tackling alcohol-fuelled violence in Sydney.

Under the new rules, which have now been in place for a week, patrons are unable to enter licensed premises in the city after 1:30am and alcohol cannot be served after 3:00am.

Nightclub owner Tal Chalak says patron numbers are already down after one week.

"We expected that a lot of people weren't going to come in the first week of lockout," he said.

"So business tonight is much quieter than usual."

Mr Chalak says he thinks restricting the sale of alcohol will also drive up demand on the street for illegal drugs.

Kings Cross bouncer George says he has lost work as a result of the crackdown and will have to get a new job.

"I've lost four hours on my hourly security work and that's a lot for me," he said.

But police say the new measures are already working.

Assistant Police Commissioner Mark Murdoch says police are happy with last night's results.

"[There are] far fewer drunk people, less agro, better behaviour," he said.

But he says police will not be complacent.

"What we saw last night is just the beginning," he said.

"We're not getting carried away at this particular point in time."