Neil Patrick Harris Dr. Douglas "Doogie" Howser Actor Max Casella Vinnie Delpino Actor Belinda Montgomery Katherine O'Brien Howser Actor James B. Sikking Dr. David Howser Actor Kathryn Layng Nurse Mary Margaret "Curly" Spaulding Actor Lawrence Pressman Dr. Benjamin Canfield Actor Lisa Dean Ryan Wanda Plenn Actor Lucy Boryer Janine Stewart Actor Mitchell Anderson Dr. Jack McGuire Actor Markus Redmond Raymond Alexander Actor