Preethi Reddy was last seen on CCTV waiting in line at McDonald's in George Street on Sunday.
A 32-year-old Indian-origin dentist has been missing from Sydney's busiest area, prompting police to launch a search operation, according to a media report.
Preethi Reddy was last seen on CCTV waiting in line at McDonald's in George Street around 2.15 am on Sunday.
A New South Wales (NSW) Police spokeswoman described Ms Reddy's disappearance as "out of character" and said there were serious concerns of her welfare.
Her work colleagues said they were "terrified" and had been unable to sleep since her disappearance.
"It's devastating, and this is completely out of character," dental assistant Chelsea Holmes of Glenbrook Dental Surgery was quoted as saying by the Australian Broadcasting Corporation.
"We got a call on Monday asking if she had turned up to work… and now we are just hoping and none of us have been able to sleep.
"I spoke to her last Thursday and it was 'see you next week' and completely normal," she said adding, "Now I am just praying she will be found," Ms Holmes said.
The NSW police said they were appealing for information in relation to her whereabouts.
Ms Reddy attended a dental convention at St Leonards at the weekend, and last spoke with her family about 11 am on Sunday, saying she planned to head home after having a late breakfast in Sydney, according to the police.
She was reported missing to Nepean Police Area Command later that night after she failed to arrive home, police added.
She was captured on CCTV inside the restaurant and appeared to leave alone a short time later.