Howard Rollins, an actor who was nominated for an Academy Award in 1981 for his work in the film ''Ragtime'' and was written out of the hit television series ''In the Heat of the Night'' in 1993 because of drug problems, died on Sunday at St. Luke's Hospital in Manhattan. He was 46.

A hospital spokeswoman, Sandra Salisbury, said that Mr. Rollins was admitted on Saturday but that his family had asked that no information be given out on the cause of death. Larry Bloustein, a spokesman for the William Morris Agency in Beverly Hills, Calif., which represented Mr. Rollins, also declined to provide any information about the death.

The New York City Medical Examiner's office said the case had not been reported for inquiry, suggesting that Mr. Rollins's death was not unexpected or suspicious.

''In The Heat of the Night,'' in which Mr. Rollins played a black chief of detectives, Virgil Tibbs, working with a white Southern sheriff, played by Carroll O'Connor, was based on the 1967 movie with Rod Steiger and Sidney Poitier. The series was broadcast by NBC from 1988 to 1992, when it was picked up by CBS. Mr. Rollins was replaced in the script by Carl Weathers in 1993, and the series ran another year. Reruns are being shown on the cable television by TNT.

Mr. Rollins also played major parts in the 1984 film ''A Soldier's Story'' and in ''Ragtime,'' in which his portrait of Coalhouse Walker, a young revolutionary, brought him an Oscar nomination.

Mr. Rollins was born in Baltimore on Oct. 17, 1950. He grew interested in acting while attending Towson State College in Maryland and in 1974 moved to New York City, where he made his home.

He had several scrapes with the law involving drug abuse. In 1988, he pleaded guilty to cocaine possession in Louisiana. In 1993, he spent a month in jail for reckless driving, and in 1992 he pleaded guilty to driving under the influence of a tranquilizer. He was sentenced to two days in jail, fined $1,000 and lost his driver's license.

Mr. Rollins's other television credits included ''He's Fired, She's Fired,'' ''The Johnnie Gibson Story'' and ''Children of Times Square.'' He was nominated for an Emmy in 1982 as best supporting actor in the daytime drama ''Another World.''

Onstage he appeared in ''G.R. Point,'' ''The Mightly Gents,'' ''We Interrupt This Program,'' 'Medal of Honor Rag'' and ''Fathers and Sons.'' He also appeared in ''I'm Not Rappaport'' in London and in a Canadian production of ''Othello.''

Photo: Howard Rollins (CBS, 1992)

Howard Ellsworth Rollins