Spokeswoman JoAnne Lewis said 39 firefighters from nine agencies responded to the blaze, reported just after 10 p.m. The fire was controlled at 11:06 p.m.
There were no injuries but the blaze caused about $600,000 in damage.
Bar patrons were safely evacuated and there was no damage to the Fairfax Inn at 15 Broadway, Lewis said. A second and third alarm were called because of the buildings' close proximity to each other, Lewis said.
The fire was confined to the nightclub and damage from the flames was limited to the first and second floors of the northwest corner of the building and a significant portion of the attic, Lewis said. There was extensive smoke and water damage throughout the building, Lewis said.
The exact cause of the fire is still under investigation, Lewis said. There was $400,000 in damage to the structure and $200,000 in damage to the club's contents.
Lewis said the sprinkler system in the nightclub was operational.
The address of 19 Broadway Nightclub is actually 17 Broadway, and the building dates back to 1921.
