Their crimes included sexually abusing minors and adolescents, raping children and running a paedophile ring.
Casa Pia, a 230-year-old institution, cares for around 4,500 needy children, most of them living in dormitories at its premises around the capital, Lisbon.
The judges began by naming Carlos Silvino, a 53-year old former driver and gardener at Casa Pia, who was found guilty of sexually abusing several under age boys in the orphanage garage and then giving them money. He told the court that he in turn had been the victim of rape while himself an orphan at Casa Pia.
Silvino confessed to more than 600 crimes and incriminated the other defendants.
These included Carlos Cruz, a popular television presenter with a three-decade career in showbusiness, and Jorge Ritto, a decorated career diplomat and former UNESCO ambassador.
Three other men were also convicted of child sex abuse, including a doctor, a lawyer, and a former Casa Pia ombudsman. A 68-year-old woman, Gertrudes Nunes, the owner of a house where “orgies” were said to have taken place, was acquitted.
All six had pleaded innocent. Mr Cruz’s lawyer said his client intended to appeal.
Almost 1,000 witnesses were called during the trial, which critics say has exposed the sluggishness and inefficiency of the Portuguese justice system and shaken public trust in the country’s institutions.
Judges detailed dozens of charges of sex abuse and procuring minors for clients among a total of around 900 that were considered “proven” and sentenced the six to jail terms of between five and 18 years. The heaviest sentence went to Silvino.
Five of the 32 victims, now in their early 20s, were in court with their lawyers. One of them, a 27-year old called Ricardo, sat in the public section and cried and shook nervously during the session.
“They ruined my life,” he said afterwards. “I had to be here today.”
Pedro Namora, another victim, said: “I hope this day will allow us to show the country that the boys have told the truth from the start.”