The defendants, who did not appear in court, could be sentenced from one month to five years in prison, The New York Times reported. Five of the doctors were expected to be sentenced to time already served. Nine other doctors were acquitted.
The doctors, all Shiites, were among the thousands of people arrested during a government crackdown on pro-democracy protesters that occupied a roundabout in the capital of Manama.
Rights activists said the government's prosecution of healthcare providers demonstrated the trial was part of its campaign against political dissent. Many doctors said they were arrested and harassed simply for trying treat people wounded in the protests.
Thursday's court ruling reduced longer sentences handed down by a military court and dismissed charges including weapons possession, the Times said.
In a statement issued after the decision, the International Affairs Authority said the sentences "were primarily for their involvement in politicizing their profession, breaching medical ethics" and "their call and involvement in the overthrow of the monarchy."
Physicians for Human Rights denounced the verdict, saying 18 of the 20 doctors charged in the case reported they were tortured after their arrests.
The organization urged United States, an ally of Bahrain, to demand "measurable improvements in the human rights situation, including holding anyone who engaged in acts of torture or ill treatment accountable."