How Did Dick Van Dyke’s ‘Diagnosis Murder’ End?

DIAGNOSIS MURDER, Dick Van Dyke, 1993-2001 — Viacom Productions/Everett Collection

What To Know

The final episode of Diagnosis Murder, “The Blair Nurse Project,” aired in May 2001 and centered on a ghostly hospital mystery rather than serving as a traditional series finale.
Dick Van Dyke reflected on his role as Dr. Mark Sloan, noting initial skepticism about his casting and crediting the show’s success to the real-life camaraderie among the cast and crew, including working with his son Barry.
Although the series ended with a regular standalone episode, two follow-up TV movies aired in 2002, allowing fans to revisit Dr. Sloan and his team.

When Diagnosis Murder aired its final episode on May 11, 2001, it wrapped up eight seasons of crime-solving hospital chaos with “The Blair Nurse Project” — a strange choice, as it was a mystery that leaned into ghost stories rather than a traditional farewell, and aired in May, rather than around Halloween.

In honor of the show’s star, Dick Van Dyke‘s incredible 100th birthday, let’s dive into the final episode in honor of his special day.

What was Diagnosis Murder about?

DIAGNOSIS MURDER, Barry Van Dyke, Dick Van Dyke, 1993-2001.

Viacom/Courtesy Everett Collection

Diagnosis Murder was one of the handful of spinoffs that prove more successful than the original show. Van Dyke’s Dr. Mark Sloan first appeared on the fourth season of crime series Jake and the Fatman, which only ran for five seasons — compared to Diagnosis Murder‘s eight seasons. The show focused on Dr. Sloan, a former Army physician who finds himself constantly solving mysteries with the help of his son, a detective named Steve (Van Dyke’s real-life son, Barry).

Though the series initially struggled in ratings, a timeslot change in the third season helped bring the show to families who were happy to have Van Dyke on their TV screens once again. The show also spawned several TV movies after it was cancelled.

What happened on the final episode of Diagnosis Murder?

The finale follows a group of film students who convince medical student Alex Smith to sneak them into Community General’s old basement, so they can shoot a documentary about the disappearance of nurse Blair Lawson, a local legend about to celebrate its 25th anniversary. The students expect to create a spooky project with planted evidence, but to their surprise, their ghost-detecting equipment and Luminol react to what appears to be real blood. When they return to the basement, more strange incidents occur, including one student experiencing a mild electrical shock.

News of the unauthorized filming reaches Dr. Don Matthews, who alerts Dr. Mark Sloan (Van Dyke), pulling him into the investigation. As Mark digs deeper, director Craig Wilson is struck on the head by an unseen assailant and later reveals that he has a personal connection to Blair Lawson. That revelation pushes Mark to re-examine the decades-old disappearance and develop a new theory about what may have happened to the missing nurse. Although the episode turned out to be the show’s final chapter, it was produced as a regular standalone case, without the hallmarks of a planned series conclusion.

DIAGNOSIS MURDER, from left: Val Valentino (as Masked Magician), Dick Van Dyke, Barry Van Dyke, 'Trash TV', (S6 / E19, aired Apr 29, 1999), 1993-2001

Tony Esparza/CBS/Everett Collection

Dick Van Dyke spoke openly about how surprised some people were when he first took on the role. “Some of my friends … said it’ll never go, the public wants to see you do comedy,” he recalled, according to the Academy Foundation Interviews, “but I didn’t really believe that. I thought this character could have enough of an eccentricity in his personality that he would still be interesting to watch.”

He also credited the show’s atmosphere to the real relationships among the cast and crew. Talking about working with his son Barry, he said, “It was wonderful … the perfect way to play our relationship because we play off one another quite well. It’s just been a joy for me.” He felt the same way about the overall environment on set: “There is no stress. Everyone enjoys it … It’s a lovely place to work.” After the series ended, two additional TV movies aired in 2002, titled Diagnosis Murder: A Town Without Pity and Diagnosis Murder: Without Warning, giving fans a little more time with Dr. Sloan and his team.