But Leung Kwok-hung, a member of parliament, said a complete ban was unnecessary and that business operators should be given a choice.
He said filtration and ventilation systems that are effective in maintaining clean air indoors were now available.
"It's ridiculous that the government is not allowing restaurateurs to use those enhancement facilities to maintain a smoking area in their restaurants. They should be given a choice."
Leung plans to demonstrate against the prohibition in the next few months.
Amy Choi, 27, a law student, supports the ban because she hates breathing in second-hand smoke although she enjoys a puff when she drinks.
"I don't like people smoking next to me. It’s so smoky and smelly."
Robert Hyde, an Australian tourist and a smoker for more than 10 years, said he would continue to visit Hong Kong, home to almost seven million people, despite the ban.
"If I need to smoke, then I'll smoke outside the restaurant and then go back to enjoy my meal. It's easy."