GREGORY ZASLAVSKY, a Russian entrepreneur with black hair, fine skin and a gravelly voice, describes his 28 years of achievement in New York with no small amount of pride: the Brighton Beach restaurant, the supermarkets. But the venture of which Mr. Zaslavsky is proudest, and the only one in which he still has a hand, is the Russian bathhouse on Gravesend Neck Road.

Robert Stolarik for The New York Times
In Brighton Beach, a bathhouse war is brewing. Sandoony USA offers extra amenities.

“I was first,” he said the other day, sitting in his clammy office at the bathhouse. “Nobody else.”

The idea for the bathhouse, Russian Bath, was born in 1980, when a friend told him about an apartment building in Sheepshead Bay that had an unused swimming pool in the basement. As far as Mr. Zaslavsky knew, south Brooklyn had no Russian baths, or banyas, as they are called, despite the fact that the area was home to a growing number of immigrants from the former Soviet republics. He leased the space, cleaned out the pool, and added the steam rooms and saunas that transformed the facility into a traditional banya, complete with fiery rocks over which water is poured to create steam.

Some days, not a single person came. “Everybody was so poor then,” Mr. Zaslavsky recalled. But gradually, the local economy improved, and the bath won a devoted following. It now gets about 100 daily visitors, many of whom have been coming once a week for years and pay a basic fee of $25.

Robert Stolarik for The New York Times
Russian Bath, a decades-old mainstay, keeps regulars feeling at home.

They are, for the most part, bearish men who plod around in plastic slippers, their stomachs spilling over the top of their swimming trunks, and their skin broiled pink by the heat. They eat briny vegetables and smoked fish in a cafe near the pool, where Mr. Zaslavsky has hung photographs of famous Russian hockey and boxing stars. (“Sergei Kobozev,” he said mournfully, pointing at one picture. “Killed by the gangsters.”)

For more than two decades, Mr. Zaslavsky’s only competition was two other baths that opened in the Brooklyn communities of Sea Gate and Kensington. But in the past few years, as the number of immigrants from the former Soviet republics in New York has swelled to more than 160,000, other entrepreneurs have been watching the Russian bath market, and a small bathhouse war is brewing.

One new entrant into the fray is Alex Israel, an Azerbaijani who last year opened Sandoony USA, an 11,000-square-foot bath on McDonald Avenue near Avenue J in Midwood, and sees the bathhouse market as rich with untapped opportunities.

“I used to go to Neck Road when it opened years ago,” Mr. Israel said. “You see the place? It smells.”

For 20 years, he added, “when people talked about these kinds of places, they said: ‘Oh, they smell. They don’t change the water in the pool.’ ”

“I decided there should be something newer, where everything is safe and clean.” (The management of Mr. Zaslavsky’s bath countered that, in accordance with its license from the health department, it maintained high levels of cleanliness.)

Sandoony, which is named after a famous Moscow bath, has all the accouterments Russian bathers expect to find. Its steam rooms and pools promote the salubrious effects of alternating the body between hot and cold temperatures. Big men in small Speedos lounge about in garden chairs drinking Baltika beer, oblivious to the roar of the elevated F train.

But Sandoony also has a skylight, sleek granite tile and television screens that show Russian music videos. Young women wander about in bikinis, and Mr. Israel boasts that by advertising in local movie theaters, he has attracted a more youthful crowd.

“This kind of place used to be just for older people,” he said. “I want the kids to know it’s O.K. here. We have 5,000 towels. I have 15 people cleaning. Everything is perfect.”

Soon, however, Mr. Israel will have his own competition. Over on Sheepshead Bay Road, off Neptune Avenue in Brighton Beach, a construction crew navigated the steel beams they had already installed for Kings Spa, a 50,000-square-foot Russian bath slated to open this year. The bath is the brainchild of two husky Uzbeks, Boris Rozenguaz and his nephew Alex, and its size alone will trump its rivals.

“I had banyas in Kazakhstan and Moscow before I come to America,” Boris Rozenguaz said recently as he sat in a trailer near the site. “I know this business.” In between pouring glasses of tea, his nephew displayed an illustrated rendering of the new facility, encased in smoky glass and topped with a United Nations-like row of international flags.

“I see customers who want this,” said Moty Movtady, an Iranian developer who is working on the project with the Rozenguaz family. “Russians spend half a day of leisure at a bath, kind of like golf to the Americans. We will be more advanced than the other baths in every respect. Newer, nicer, more expensive.”

Like Sandoony, the $6 million Kings Spa hopes to entice a new generation of Russian bathgoers. It will offer services unfamiliar to older Russians, but ones their Americanized children have come to expect: tanning beds, skin care, massage. A fitness center will occupy the entire second floor.

“The American gym is geared toward younger people,” Alex Rozenguaz said. Among the older generation, he noted, simply sitting and sweating is seen as exercise enough.

ALTHOUGH the operators of all three bathhouse are presumably keeping an eye on the competition, Alex Rozenguaz predicts that there will be enough business to go around.

“We have 400 Russian restaurants in Brooklyn and only three bathhouses,” he said. “Today, if another 10 opened, they’d have enough business to survive. At one, there’s an hourlong line to get in on weekends. The market is large enough for everyone.”

The other evening, Mr. Zaslavsky’s modest basement bath on Gravesend Neck Road was nearly full. Inside the scorching Russian dry room, people sat shoulder to shoulder on wooden benches, breathing heavily and wearing felt caps to protect their heads from the heat.

Jack Bord, a Yalta-born limousine driver who lives in Midwood, explained, unblinkingly, that one must stay in the dry room “until you feel your skin is on fire or you have a heart attack.” He had heard rumors about Kings Spa, and had actually visited Sandoony a few times out of curiosity. Still, he preferred the old Russian bath that he has visited every Thursday for a decade.

“Maybe the new banyas opening are more famous, have a little bit extra service,” Mr. Bord said, ladling water over the scorching rocks until the room was shrouded in steam. “But you feel there like a stranger. I feel here at home. Why should I look for something else if I’m happy here?”