Rabinowitz grew up in Brooklyn, New York. In grade school, he was placed in a special education class due to a severe stutter; which often caused his body to twist and spasm when attempting to speak. Unable to communicate with his peers and teachers, Rabinowitz became interested in wildlife, to which he could speak. At this point, Rabinowitz made a promise to animals that if he ever found his voice, he would use it to speak in their defense.
Today, Rabinowitz frequently shares this childhood story in interviews, lectures, books and other publications to explain how he became interested in wildlife conservation.  In 2008, the video of Dr. Rabinowitz telling this story on The Colbert Report went viral, largely because it nearly brought the show's host, Stephen Colbert, to tears. Today, Rabinowitz serves as a spokesperson for The Stuttering Foundation (SFA).
In 1974, Rabinowitz received his Bachelor's degree in biology and chemistry from McDaniel College in Westminster, Maryland. Rabinowitz later attended the University of Tennessee, receiving his M.S. and Ph.D. in ecology in 1978 and 1981, respectively.
Prior to co-founding Panthera with the organization's Chairman, Dr. Thomas S. Kaplan, in 2006, Rabinowitz served as the Executive Director of the Science and Exploration Division for the Wildlife Conservation Society, where he worked for nearly 30 years.
While working in Myanmar's Hukaung Valley in 1997, Rabinowitz discovered four new species of mammals, including the most primitive deer species in the world, Muntiacus putaoensis, or theleaf deer. Rabinowitz's work in Myanmar led to the creation of five new protected wildlife areas, including the country's first marine park, Lampi Island National Park; Myanmar's first and largest Himalayan national park, Hkakabo Razi National Park; the country's largest wildlife sanctuary, Hukaung Valley Wildlife Sanctuary; the world's largest tiger reserve and one of the largest protected areas in the world, Hukaung Valley Tiger Reserve, and Hponkhan Razi National Park, an area which connects Hukaung Valley and Hkakabo Razi for a contiguous protected area of more than 5,000 square miles, called the Northern Forest Complex.
Rabinowitz also established the world's first jaguar sanctuary  — the Cockscomb Basin Jaguar Preserve— in Belize and the Tawu Mountain Nature Reserve, Taiwan's largest protected area and last piece of intact lowland forest. In Thailand, he conducted the first field research on Indochinese tigers, Indochinese leopards, and Asian leopard cats, leading to the designation of the Huai Kha Khaeng Wildlife Sanctuary as a UNESCO world biosphere reserve.
One of Dr. Rabinowitz's greatest achievements was the conceptualization and implementation of the Jaguar Corridor, a series of biological and genetic corridors for jaguars across their entire range from Mexico to Argentina. Dr. Rabinowitz also initiated Panthera's Tiger Corridor Initiative, an effort to identify and protect the world's last remaining large interconnected tiger landscapes, with a primary focus on the remote and rugged Indo-Himalayan region of Asia.
Rabinowitz's project to establish a chain of protected tiger habitat across the southern Himalaya was the focus of the BBC Natural History Unit's 2010 documentary series Lost Land of the Tiger. An expedition team spent a month investigating the status of big cats in Bhutan, leading to the discovery of tigers living at much higher altitudes than previously realized.