Perkins began his zoo career in 1926, literally working from the ground up with the St. Louis Zoological Gardens. He was put to work on the Zoo's laborer crew, where he helped maintain the zoo grounds. Perkins quickly rose through the Zoo's ranks, becoming curator of reptiles in 1928. In 1944, following seven years as curator of the New York Zoo in Buffalo, N.Y., Perkins was appointed director of the Lincoln Park Zoo in Chicago. Under Perkins' direction, the Zoo became internationally known, in part from the Zoo Parade television series, which ran on NBC from 1949-1957.

Perkins' career came full circle in 1962, when he returned to the St. Louis Zoo as its director. He became director emeritus of the Zoo in 1970. It was during Perkins' tenure with the St. Louis Zoo that he, along with producer Don Meier, began work on an idea for a new television program. Mutual of Omaha's "Wild Kingdom" debuted on January 6, 1963, and was in original production for 27 years. The program received four Emmys from the National Academy of Television Arts and Sciences and was the first television series to receive the National Parent Teacher Association's (PTA) "Recommended for Family Viewing" designation.

Marlin Perkins passed away in 1986 at the age of 81.