Inspired by a growing interest in natural history in the early 1850s, a small group of Frankfurt citizens seized on the idea of building a zoo in the city. By 1857 all that stood in the way of a zoo was the approval of the city government, which had no objections to the plan to hold bears, wolves and boar in appropriate enclosures. In October of the same year, the Society began issuing shares and in the following months 246 shareholders invested a total of 80,000 Gulden in the project. The first general meeting on March 7, 1858 made it official - the Frankfurt Zoo was born.

The Frankfurt Zoo opened its doors just five months after the founding of the Society. This "pilot zoo" was not located at the Zoo's current site, but rather outside the city on a 15-acre parcel of land just west of the Bockenheimer Tor. Despite various difficulties, the first few years of operation showed that a Zoo could survive in Frankfurt, and when the lease ran out on the property being used, the search began for a new home. For legal reasons it was necessary to form a "New Zoological Society," which then merged with the "Zoological Gesellschaft of 1858" at its first general meeting on October 31, 1873. It was the New Zoological Society that under constraints of time and money succeeded in building and relocating the Zoo to its present location. In February 1874, the animals made the journey to their new sanctuary at Pfingstweide. The first years were difficult for the Zoo. Visitor numbers were well below expectations and by late 1881 the Society would have faced insolvency if the city of Frankfurt had not stepped in with a refinancing plan.

The city was called to action to save the Society once again in 1888 with a new contract, after which all of the Zoo's profits flowed back to the city. Frankfurt Zoological Society operated the Frankfurt Zoo until the First World War. The war closed the debate on moving the Zoo once again and also let to a decline in revenues that finally bankrupted the Society. In the summer of 1915, the city took over complete control of the Zoo and the Society was dissolved as a joint-stock company. But despite the demise of the Society as a legal entity, the shareholders continued to maintain their interest in and support of the Zoo.

An important shift in thinking about zoos came about in 1923. For the first time, it was recognized that zoos could contribute to the protection of animals living in the wild. Already during the war years, zoo directors had feared for the survival of the wisent, an European bison species native to Germany. Frankfurt Zoo director Dr. Kurt Priemel, who had collected information on these threatened animals, was named president of the newly founded "International Society for Wisent Protection." In 1923 he wrote, "All efforts toward the great and glorious idea of nature protection must remain incomplete unless they are pursued on the basis of internationalism. Today, nature protection is not only an undeniable challenge to our time, but has advanced to become a generally accepted science." These words have lost none of their relevance today. After the joint-stock company was disbanded in 1915, many friends of the Zoo continued in the tradition of the Society by making generous donations. Heavy bombing during the night of March 18, 1944 destroyed nearly all of the files of the Zoo and the Zoological Society.

On May 1, 1945, a veterinarian from Upper Silesia, Dr. Bernhard Grzimek, was appointed director of the Frankfurt Zoo. During his first years as director, he was primarily concerned with rebuilding the Zoo, which had been completely destroyed. Much of the necessary construction was made possible by funds donated by friends of the Zoo, who had once again begun to meet regularly after the war. On February 15, 1950, these patrons joined together to form the "Society of Friends and Supporters of the Zoological Gardens e.V.," which raised badly needed money for the Zoo. On the occasion of the 100th anniversary of the defunct Zoological Society, the decision was made to revive the traditional name of the original Society. Beginning in 1958 there was once again a "Frankfurt Zoological Society," later amended to "Frankfurt Zoological Society of 1858" - FZS for short.
The early post-war years find Grzimek and his son Michael travelling to Africa to observe, photograph and shoot documentary footage of animals in their natural habitat. These trips and the corresponding recognition that only global protection can preserve wild animal populations become the new focus of the activities of the Frankfurt Zoological Society: nature conservation.

Following the death of Michael Grzimek in a tragic plane accident in East Africa, FZS established a memorial fund in his name in 1960. The fund was the precursor of the special trust created a year later as "Help for Threatened Wildlife." In his television programmes, Prof. Grzimek solicited donations to this fund, which formed the basis for the further work of FZS. The early work of the Society was concerned primarily with establishing a nature conservation infrastructure in East Africa, but soon projects were launched in other regions of the world, such as Galapagos, South America and Asia, and back home in Hessia as well. Grzimek's popularity and his television series "A Place for Animals" (Ein Platz für Tiere) continue to generate donations and bequests today. Particularly during the tenure of Dr. Richard Faust, FZS was able to continuously build its endowment and to take on an increasing number of projects. The Society supported 70 projects in 2001, investing about 4 million euros in nature conservation in 30 countries around the world. A new milestone was passed on March 30, 2001 with the creation of a new foundation - "Help for Threatened Wildlife." Approximately 33 million euros stemming from the assets of the FZS now endow the foundation and ensure the financial basis of our projects for all time.