Greg Giraldo

Greg Giraldo, a comedian famous for his stinging insult humor, disgruntled rants and frequent appearances on Comedy Central’s highly watched roast series, died on Wednesday at Robert Wood Johnson University Hospital in New Brunswick, N.J. He was 44.

Mr. Giraldo had been hospitalized since Saturday night after he was found unconscious in a hotel room in New Brunswick, where he was scheduled to perform at a club. Mr. Giraldo had suffered a drug overdose, The Home News Tribune of East Brunswick, N.J., reported, citing New Brunswick police. The precise cause of death on Wednesday was unclear. A hospital spokesman said the family declined to release that information.

A former lawyer who gave up a job at a law firm to pursue comedy, Mr. Giraldo became a wildly successful stand-up comic touring the country as a headliner at many clubs and dispensing his own brand of sharp and often brutal humor. As Mr. Giraldo’s following grew so did his presence on radio and television. He performed more than a dozen times on “The Late Show With David Letterman” and “Late Night With Conan O’Brien” and become a radio regular on “The Howard Stern Show.”

Mr. Giraldo was particularly known for his clever and exasperated rants, which he used to great effect on Comedy Central shows like “Tough Crowd With Colin Quinn” and Lewis Black’s “Root of All Evil.” But it was his regular appearances on that network’s roast series — one of Comedy Central’s most successful shows — that drew particular attention. Mr. Giraldo was a mainstay on that series, taking the stage in more than a half-dozen shows to mercilessly ridicule pop-culture figures like Pamela Anderson, William Shatner, Chevy Chase — “I could only dream,” he told Mr. Chase, of making “three good movies” and 40 horrible ones — and, in 2009, a fellow comedian, Larry the Cable Guy.

“Some people say Larry’s only successful because he’s pandering to the lowest common denominator,” Mr. Giraldo said. “Don’t listen to these people, Larry. They’re just bitter and jealous and right.”

Mr. Giraldo’s fame grew quickly, and by 2010 he was making prime-time appearances on network television. Earlier this year he was a judge on the NBC reality show “Last Comic Standing” and a panelist on “The Marriage Ref,” the Jerry Seinfeld brainchild that also airs on NBC.

But Mr. Giraldo’s humor had a dark side, which he sometimes referenced in his stand-up act. He had been a heavy drinker, but in interviews in recent years he spoke of being sober — with occasional slip-ups.

Mr. Giraldo was born in New York in 1965. He earned a bachelor’s degree from Columbia and a law degree from Harvard. He was divorced with three children.

As something of a running joke, Mr. Giraldo was often needled by fellow roasters on Comedy Central for being the comedian no one had ever heard of. But on Twitter Wednesday night, “R.I.P. Greg Giraldo” was the top trending topic, and his fans posted countless notes and tributes on his YouTube videos and Facebook and MySpace pages.

Mr. Giraldo’s last major appearance on Comedy Central was in August during “The Comedy Central Roast of David Hasselhoff,” in which he hectored Mr. Hasselhoff about his own alcohol abuse.

“You used to have a car that started when you talked to it; now you have a car that won’t start when you blow into it,” he said.

Mr. Giraldo was one of the most widely praised and talked about comedians on the roast that evening. The show drew 3.5 million total viewers and was the highest-rated cable show of the night.