Actor Neil Patrick Harris reportedly drew inspiration from watching Robert Young in Docteur Marcus Welby (1969). Learning that Young was ill and pondering death, Harris visited Young with tapes of this show and helped cheer him up.
Steven Bochco partially modeled the character of Doogie Howser after his father, who had been a child prodigy as a violinist.
Although Doogie and Vinnie were supposed to be the same age, Neil Patrick Harris is six years younger than Max Casella. Harris was sixteen during the first season, and Casella was twenty-two.
One of the first sitcoms that did not have an audience or any laugh track.
In 2008, Neil Patrick Harris appeared in television and print ads for Old Spice deodorant, spoofing his Doogie Howser character, stating he could recommend the product as a "former make-believe doctor" because he "used to be a pretend doctor." He is also shown trying to use a stethoscope on a patient's nose instead of his chest.