John Dolittle, MD, is a respected physician and quiet bachelor living with his spinster sister in the small English village of Puddleby-on-the-Marsh. His love of animals grows over the years and his household menagerie eventually scares off his human clientele, leading to loss of wealth. But after learning the secret of speaking to all animals from his parrot Polynesia, he takes up veterinary practice. His fortunes rise and fall again after a crocodile takes up residence, but his fame in the animal kingdom spreads throughout the world. He is conscripted into voyaging to Africa to cure a monkey epidemic just as he faces bankruptcy. He has to borrow supplies and a ship, and sails with a crew of his favourite animals, but is shipwrecked upon arriving to Africa. On the way to the monkey kingdom, his band is arrested by the king of Jolligingki, a victim of European exploitation who wants no white men traveling his country. The band barely escapes by ruse, but finally makes it to the monkey kingdom where things are dire indeed with the raging epidemic. He vaccinates the well monkeys and finally nurses the sick back to health. In appreciation, the monkeys find a pushmi-pullyu, a shy two-headed gazelle-unicorn cross, whose rarity may bring Dr. Dolittle money back home. Setting off on the return trip, they again are captured in Jolliginki. This time they escape with the help of Prince Bumpo, who gives them a ship in exchange for Dolittle's bleaching his face white, his greatest desire being to act as a European fairy-tale prince. Dolittle's crew then have a couple of run-ins with pirates, leading to Dolittle's winning a pirate ship loaded with treasures and boy whose uncle was abandoned on a rock island. After reuniting the two, Dolittle finally makes it home and tours with the pushmi-pullyu in a circus until he makes enough money to retire to his beloved home in Puddleby.