Arnold Klein was born on February 27, 1945, in Mt. Clemens, Michigan, the son of a Jewish Orthodox rabbi. He was raised in Michigan and North Miami, Florida, graduating from North Miami High School in 1963. In 1967, Arnold Klein earned his Bachelor’s degree in Biology from the University of Pennsylvania. He attended the University of Pennsylvania School of Medicine, earning his Doctor of Medicine degree in 1971. He completed an internship at Cedars-Sinai Medical Center in Los Angeles and his residency in dermatology at the University of Pennsylvania and the University of California at Los Angeles (UCLA). In 1975, he served as Chief Resident in Dermatology at UCLA. Arnold Klein was an unpaid, volunteer professor of Medicine and Dermatology at the UCLA David Geffen School of Medicine. Klein was an outspoken critic of the misuse of prescription drugs, toxins, and certain synthetic dermal fillers, including ArteFill. He was responsible for the FDA giving Allergan’s Botox a black box warning. Arnold Klein was named a consultant to the FDA. He died on October 22, 2015 at the age of 70 at the Eisenhower Medical Center in Rancho Mirage, California. In August 1985, Klein joined the board of the Los Angeles-based National AIDS Research Foundation (NARF). A month later, the Foundation merged with the New York-based AIDS Medical Association, now known jointly as AmfAR, The Foundation for AIDS Research. As of 2012, Klein was also a member of the Advisory Board of the AIDS Services Foundation Orange County. Over the next two decades, they additionally established the Elizabeth Taylor AIDS Foundation and Art for AIDS in Orange County.

In 2007, Arnold Klein founded The Elizabeth Taylor Endowment for the UCLA CARE Center, a facility that focuses on advancing HIV/AIDS research and treatment. In the November 2008 issue of L’Uomo Vogue, in an article related to AIDS in Africa, it was reported that Klein and the organizations which he founded have raised in excess of $274 million for HIV research and care. Klein served as a trustee to various boards of directors, some of which included the Jennifer Jones-Simon Foundation and The Hereditary Disease Foundation. Klein, alongside his old friend Frank Gehry, helped the foundation to raise funds and awareness for inherited diseases. Klein also co-founded the Rose Tarlow-Arnold W. Klein Breast Cancer Foundation at UCLA which provides breast cancer treatment for individuals who are unable to afford it. He has received numerous awards and honors including Who’s Who in the World, Best Doctors in America, Men of Achievement, AIDS Services Foundation of Orange County, Award of Merit, Los Angeles Magazine, The Best of L.A., Los Angeles Business Journal, 10 Masters of Medicine in Los Angeles, Haney Scholar, University of Pennsylvania, Inaugural Visiting Professor in Cosmetic Dermatology, Harvard School of Medicine, Inaugural Visiting Professor in Cosmetic Dermatology, University of Vermont, Measey Scholar, University of Pennsylvania, Philadelphia Foundation Fellow, Public Health Service Post – Doctoral Fellow, and Top Doctors of America. In 2004, Klein was given a chair in his name at the UCLA Division of Dermatology.