The renewed look at Wood's Nov. 29, 1981, death was prompted by new information detectives received about the case, Los Angeles County sheriff's spokesman Steve Whitmore said Thursday.
No additional details were provided, but a detective planned to hold a news conference Friday, and anyone with information about the case was being asked to contact sheriff's officials.
A spokesman for Wood's husband at the time of her death, Robert Wagner, said the family trusts the sheriff's department will take appropriate action but has not been contacted about the case being re-opened.
Wood drowned after a night of partying with husband Wagner and "Brainstorm" co-star Christopher Walken on the couple's yacht anchored off Santa Catalina Island. Her death was ruled an accident and it was determined that she had been drinking before her death.
The office wrote that Wood was "possibly attempting to board the dinghy and had fallen into the water, striking her face."
A dinghy that had been attached to the couple's yacht, "Splendor," was found in a Catalina cove.
The Los Angeles Times reported that detectives were prompted to look at the case again after comments by the ship's captain, Dennis Davern. He was recently interviewed for a collaboration between the magazine Vanity Fair and the television series "48 Hours Mystery" that focuses on Wood's death.
"Although no one in the Wagner family has heard from the LA County Sheriff's department about this matter, they fully support the efforts of the LA County Sheriff's Dept. and trust they will evaluate whether any new information relating to the death of Natalie Wood Wagner is valid, and that it comes from a credible source or sources other than those simply trying to profit from the 30 year anniversary of her tragic death," Wagner spokesman Alan Nierob wrote in a statement.
Wood, a three-time Oscar nominee famous for roles in "West Side Story," "Rebel Without a Cause" and other Hollywood hits, was 43 when she died. She and Wagner, star of the TV series "Hart to Hart," were twice married, first in 1957 before divorcing six years later. They remarried in 1972.
Wood's drowning sparked tabloid speculation that foul play was involved, but Wagner and Wood's sister have dismissed any suggestion there was foul play.
Laura Wood wrote in a biography on her sister, "What happened is that Natalie drank too much that night."
Wagner wrote in a 2009 autobiography that he blamed himself for his wife's death.
Phone and email messages to Walken's publicist were not immediately returned. Attempts to contact Davern were unsuccessful.