A few yards away, hundreds of families displaced by the earthquake languished under tents and tarps, bathing themselves from buckets and relieving themselves in the street as barefoot children frolicked on pavement strewn with garbage.

This is the Pétionville district of Port-au-Prince, a hillside bastion of Haiti’s well-heeled where a mangled sense of normalcy has taken hold after the earthquake in January. Business is bustling at the lavish boutiques, restaurants and nightclubs that have reopened in the breezy hills above the capital, while thousands of homeless and hungry people camp in the streets around them, sometimes literally on their doorstep.

“The rich people sometimes need to step over us to get inside,” said Judith Pierre, 28, a maid who has lived for weeks in a tent with her two daughters in front of Magdoos, a chic Lebanese restaurant where diners relax in a garden and smoke flavored tobacco from hookahs. Chauffeurs for some of the customers inside lined up sport utility vehicles next to Ms. Pierre’s tent on the sidewalk near the entrance.

Haiti has long had glaring inequality, with tiny pockets of wealth persisting amid extreme poverty, and Pétionville itself was economically mixed before the earthquake, with poor families living near the gated mansions and villas of the rich.

But the disaster has focused new attention on this gap, making for surreal contrasts along the streets above Port-au-Prince’s central districts. People in tent camps reeking of sewage are living in areas where prosperous Haitians, foreign aid workers and diplomats come to spend their money and unwind. Often, just a gate and a private guard armed with a 12-gauge shotgun separate the newly homeless from establishments like Les Galeries Rivoli, a boutique where wealthy Haitians and foreigners shop for Raymond Weil watches and Izod shirts.

“There’s nothing logical about what’s going on right now,” said Tatiana Wah, a Haitian planning expert at Columbia University who is living in Pétionville and working as an adviser to Haiti’s government. Ms. Wah said the revelry at some nightclubs near her home, which are frequented by rich Haitians and foreigners, was now as loud — or louder — than before the earthquake.

The nongovernmental organizations “are flooding the local economy with their spending,” she said, “but it’s not clear if much of it is trickling down.”

Aleksandr Dobrianskiy, the Ukrainian owner of the Bagheera casino here in the hills, smiled as customers flowed in one recent Saturday evening, drinking Cuba Libres and plunking tokens into slot machines.

He said business had never been better, attributing the uptick at his casino to the money coming into Haiti for relief projects. That spending is percolating through select areas of the economy, as some educated Haitians get jobs working with relief agencies and foreigners bring in cash from abroad, using it on housing, security, transportation and entertainment.

“Haiti’s like a submarine that just hit the bottom of the sea,” said Mr. Dobrianskiy, 39, who moved here a year ago and carries a semiautomatic Glock handgun for protection. “It’s got nowhere to go but up.”

Sometimes the worlds of haves and have-nots collide. Violent crime and kidnappings have been relatively low since the earthquake. But when two European relief workers from Doctors Without Borders were abducted outside the exclusive Plantation restaurant this month and held for five days, the episode served as a reminder of how Haiti’s poverty could give rise to resentment and crime.

The breadth of Haiti’s economic misery seemed incomprehensible to many before the quake, with almost 80 percent of the population living on less than $2 a day. A small elite in gated mansions here in Pétionville and other hillside districts wields vast economic power.