National Capital District Governor Powes Parkop says he wants to hold liable businesses and people who transport the nut into the city.
Betel nut - or buai - is consumed throughout Papua New Guinea. Locals chew it with lime and a mustard stick, which produces a blood red liquid that is then spat out pretty much everywhere.
Chewing the combination of ingredients is widely blamed for high incidents of mouth cancer and the spread of tuberculosis in the Pacific Island nation.
"It's a liability and a health hazard," Mr Parkop told AAP last week.
"I have a situation where one-third of the reported tuberculosis cases are found in the city.
"That's sad and embarrassing. We're the nation's capital, we're supposed to lead by example."
Mr Parkop first issued a ban on chewing betel nut in January, but - along with a ban on public smoking - it was widely ignored.
Now he wants special zones for chewing to be set up in the surrounding Central Province.
"We've been trying to get betel nut vendors in a certain part of the city, and we're trying to get chewers to chew in their own home.
"But it's not working. The traders don't want to be regulated; they are trading anywhere and everywhere."
Betel nut chewing is already banned within the city limits of Lae and Mt Hagen, PNG's second and third largest cities.
Mr Parkop said in other areas, such as Kokopo in New Britain province, betel nut is chewed regularly but not spat on the ground.
Port Moresby already spends about $25,000 a week cleaning up the city.
Mr Parkop says if the latest ban falls short, he is considering importing a beetle to devour the buai crops, for the one-off price of $25,000.
He says while using a beetle to eat the crops will save the city money, he hasn't "warmed to (the idea) yet. That's the last card I can play." [PNGatitude]