Walter Koenig's cause of death has been revealed after he was laid to rest in the same cemetery as his late son.
The Star Trek icon, best known for playing Pavel Chekov on the original series, died on October 25, 2026, aged 90, at his home in North Hollywood, with his daughter Danielle and his niece by his side, his representative confirmed at the time.
According to his death certificate obtained by TMZ, Walter died of cardiopulmonary arrest, with chronic diastolic congestive heart failure listed as an underlying cause.
Acute renal failure was also listed as a significant contributing factor to his death.
The document also revealed that Walter was cremated on October 30, with his ashes placed at the Hollywood Forever Cemetery in Los Angeles, where his son, Andrew, was laid to rest after he died by suicide in 2010 at age 41.
© Getty ImagesWalter's death was announced on October 26 by his representatives, who said in a statement: "Today we mourn the passing of Walter Koenig, whose talent, warmth, and unforgettable performances left a lasting mark on generations of fans around the world.
"Best known for his iconic role as Pavel Chekov in Star Trek: The Original Series, Walter helped inspire audiences with his optimism, humor, and adventurous spirit."
The statement continued: "Beyond Star Trek, his long and distinguished career showcased his versatility as an actor and his genuine love for his craft.
© Getty Images"His remarkable talent continued to shine in his later years, most recently with his performance in the short film Mr. Fleischmann, for which he received the Platinum Award for Best Actor at the 2026 Independent Shorts Awards – a fitting recognition of a lifetime devoted to his craft.
"Walter’s legacy extends far beyond the screen. Through countless convention appearances and interactions with fans, he shared his kindness, wit, and appreciation with everyone fortunate enough to meet him.
'He understood what Star Trek meant to people and embraced the community that grew around it."
Star Trek's surviving members pay tribute
© InstagramFollowing the news of his death, Walter's former co-stars and the only two living members of Star Trek: The Original Series, William Shatner and George Takei, paid touching tributes.
George, who played fellow crew member Hikaru Sulu, penned: "Walter and I met on the bridge of the Enterprise in the 1960s, and we stayed friends for nearly six decades.
"When Brad and I married in 2008, Walter stood beside us as our best man. Just last month, on Sept. 14, he turned 90, on the same day Brad and I celebrated our 18th wedding anniversary. I will always treasure that he and I shared that date."
He added: "Walter was more than Chekov. He was a writer, a teacher, a thoughtful man, and a loyal friend. To the fans who loved him for so many years, thank you. He loved you too."
© NBCU Photo Bank/NBCUniversalWilliam said that while he and Walter "did not know each other well away from the set," he was still "deeply saddened" to learn of his passing.
"What I observed, and what so many fans have expressed over the years, was a man who genuinely loved the Star Trek community," he continued.
"At conventions, Walter was rarely content to remain behind a signing table. He preferred to be among the people who had kept Star Trek alive for so many decades. That kind of genuine connection is rare, and it will be remembered by everyone who came into contact with him."
He concluded: "My condolences to his family, his friends, and the countless fans whose lives he touched."
