A regional criminal court in Neuchatel canton ruled the doctor had no choice when she took the final step to end the life of a terminally ill patient, swissinfo.com reported Tuesday.
The doctor began a lethal drip for a patient suffering from an incurable degenerative condition who had expressed her wish to die.
Since the patient was unable to perform the act herself, the doctor relied on a movement of the patient's foot as a signal.
The court ruled there was no doubt about the patient's wishes and the doctor had a medical and moral duty to break the law out of compassion.
Direct active euthanasia is illegal in Switzerland but assisted suicide and passive euthanasia, or mercy killing, are not.
Sen. Didier Berberat, who represents Neuchatel canton, has urged the Swiss Cabinet to change the penal code that punishes those who assist in another's suicide with three years in jail or a fine.
He listed possible restrictions to be incorporated into any new law: The person willing to die must have an incurable disease, the disease must be in a terminal phase and the patient must be suffering excruciating pain but still capable of making judgments.