By SCOTT SAYARE
and MAIA de la BAUME

PARIS - The neighbors do not like the Zero Zero bar, a graffiti-plastered dive on an otherwise sleepy stretch of Rue Amelot, in the 11th Arrondissement. It is because of the noise. The neighbors have been known to pelt the Zero Zero’s patrons with eggs and to dump water on their heads from balconies.

“It’s insane; the neighbors take us for crazy people,” said Nicolas Dechambre, 26, a co-owner and bartender at the bar.

The club has paid close to $12,000 in fines for street noise in the past year and a half, he said, and has been closed by the police for a cumulative period of nearly two months, the result of complaints from neighbors.

“Paris, it’s not the City of Lights anymore,” Mr. Dechambre said. “It goes to sleep at 11.”

Faced with mounting noise complaints, fines and closings, many Parisian bars and concert halls are struggling to stay afloat. D.J.’s and musicians have also been abandoning the French capital, forcing a startling conclusion upon the city’s night life professionals: Paris may soon be dead at night.

The city has set up a Web portal, Paris Nightlife, to promote its 7,500 bars, nightclubs and concert halls, an effort to “reglorify the night,” said Audrey Epeche, a city tourism adviser.

That, however, seems unlikely to remove the many impediments to the French capital’s party scene, laid out in a city-commissioned study on the night life economy by the French School of Economic Warfare.

A sampling of the city’s problems: densely packed, mixed-zoned neighborhoods; a lack of late-night transportation ; and an unwieldy tangle of rules and regulations on bars and nightclubs . All of these tensions have been exacerbated by the 2008 tobacco ban, which has sent smokers onto the sidewalks at all hours of the night.

The recent report on the night life economy ranked Paris well behind Berlin - as well as London, Amsterdam and Barcelona, Spain - in terms of “nocturnal attractiveness.”

Anouar Hajoui, a French hip-hop D.J. known as Cut Killer, said he all but gave up performing here several years ago. “There’s stuff going on,” he said, “but not that much.”

A 2008 tobacco ban sent legions of smokers onto Paris’s streets, causing a spike in noise complaints and fines, club owners say. / PIERRE TERDJMAN FOR THE NEW YORK TIMES