He began working for the family's Berlitz School of Languages, during college breaks. The publishing house, of which he was vice president, sold, among other things, tourist phrase books & pocket dictionaries, several of which he authored. He also played a key role in developing record & tape language courses. He left the company in the late 1960s, not long after he sold the company to publishing firm Crowell, Collier & Macmillan. He graduated magna cum laude from Yale Univ.
Berlitz was a writer on anomalous phenomena. He wrote a number of books on Atlantis. In his book The Mystery of Atlantis, he used evidence from geophysics, psychic studies, classical literature, tribal lore, archeology & mysteries & concluded that Atlantis was real. Berlitz also attempted to link the Bermuda Triangle to Atlantis. He claimed to have located Atlantis undersea in the area of the Bermuda Triangle. He was also an ancient astronaut proponent who believed that extraterrestrials had visited earth.
Berlitz spent 13 years on active duty in the US Army, mostly in intelligence. In 1950, he married Valerie Seary, with whom he had a daughter, Lynn. He died in 2003 at the age of 89 at University Hospital in Tamarac, FL.