The show followed the work of Dr. Tracy, his daughter Paula (Cheryl Miller), and his staff, who were frequently forced to protect animals from poachers and local officials. Tracy's pets, a cross-eyed lion named Clarence and chimpanzee Judy, were also popular characters.
Daktari was based upon the 1965 film Clarence, the Cross-Eyed Lion, which also starred Thompson as Dr. Tracy. The concept was developed by producer Ivan Tors, inspired by the work of Dr. A.M. "Toni" Harthoorn and his wife Sue at their animal orphanage in Nairobi. Dr. Harthoorn was a tireless campaigner for animal rights, and with his research team developed the capture gun, used to sedate animals in order to capture them without injury.
In the show's final season, child star Erin Moran joined the cast as Jenny Jones, a seven-year-old orphan who becomes part of the Tracy household.