The 52-year-old man was convicted of 211 counts of violation of privacy using a recording device, the court in the eastern city of Gera said.
The dentist had installed a video camera in the changing room of his practice which was used by his female hygienists and receptionists.
His staff discovered the camera last year and reported it to the police.
Investigators found nearly 7,500 video files on the defendant’s computer going back six years, showing eight victims in their underwear or naked.
“The eyes of another have no place in a changing room,” presiding judge Siegfried Christ said as he read the verdict, according to German news agency DPA.
“You get the sense that you have two passions – being a dentist and being a peeping Tom,” he told the defendant.
Christ said the dentist had shown no remorse during the trial.
Prosecutors had demanded a three-year jail sentence while the defence called for an acquittal.
The man, who was not identified by the court, is still practising dentistry but will likely now lose his licence.
He may appeal the verdict.