The New York-based rights group accused President Bashar al-Assad's forces of "systematically" targeting hospitals, clinics and medical personnel since the conflict began in 2011.
Over the past four years, a total of 610 medical personnel were killed, 139 of whom were tortured or executed, according to the report.
It also documented 233 attacks on 183 hospitals and clinics, most recently with the use of deadly barrel bombs.
"The Syrian government has resorted to every tactic: emergency-room arrests, hospital bombings -- including barrel bombs -- and even the torture and execution of doctors who attempt to treat the wounded and sick," said Erin Gallagher, director of investigations for Physicians for Human Rights (PHR).
More From This Section
Attacks on medical workers are a violation of international humanitarian law, but the rights group noted that "when the attacks are as widespread and systematic as they are in Syria, they constitute crimes against humanity."
The release of the report partly compiled from data from PHR's "field sources" inside Syria came as the war enters its fifth year with little prospect for peace.
Attacks on medical staff and hospitals have devastated the medical infrastructure, said the report entitled "Doctors in the Crosshairs: Four years of Attacks on Health Care in Syria."
"World leaders must not allow this onslaught against medical personnel to become the new normal in conflict," said PHR executive director Donna McKay.
2013 stands out as the deadliest year for doctors in Syria, with 171 medical personnel killed including Osama Baroudi, a prominent gastroenterologist who was tortured and died in custody in July.