Beverly Hills Plastic Surgeon Dead at 68

A well-known Beverly Hills plastic surgeon has died after a neck surgery took a turn for the worse ... TMZ has learned.

According to the Los Angeles County Medical Examiner ... Ronald Moy died on June 23rd -- with the cause of death listed as "complications of neck surgery."

The death was ruled as accidental. Moy passed away at a hospital -- the exact circumstances surrounding the fatal surgery remain unclear.

Moy is described on his website as "one of the leading cosmetic and facial plastic surgeons in Los Angeles." The doctor specialized in facelifts, liposuction, laser skin resurfacing, eye lifts, and Mohs micrographic surgery.

He had an impressive resume in academia ... previously serving as a professor at the David Geffen School of Medicine at UCLA and publishing more than 200 articles on cosmetic and dermatologic surgery and treatments.

Moy's practice grew a substantial social media following ... where he's seen giving skincare tips and cosmetic advice. He also reportedly worked with celebs in the past -- providing treatments like DNA facials to A-listers such as Christina Aguilera and Lea Michele.

Moy was 68.