The ADMD, which counts 48,000 members across France, organised the protest at the Republique square in the east of Paris.
A band of trumpets and tubas rang out, as demonstrators made their way to the nearby Cirque d’hiver for an organised meeting.
There, presidential candidates Jean-Luc Melanchon and Eva Joly were on the bill to speak in support of assisted suicide.
The ADMD called the demonstration to alert Paris’s Elysee Palace that they want euthanasia to be made legal in France, ahead of the presidential elections in April and May.
On the other side of town near Trocadero in the west of the city, another organisation united around 500 people to protest against euthanasia.
Alliance Vita members dressed up as sad clowns to show their disapproval of the practice, which is still illegal in France.
Groups against euthanasia want the medical profession to improve palliative care to relieve end of life suffering and pain, instead of focusing on intentionally ending a life.
A law does exist in France to address patients who are in a persistent vegetative state or coma.
The Leonetti law was written in 2005 to allow patients or family members to end treatments that may be artificially keeping a person alive. The law does not, however, address euthanasia or terminating a life voluntarily.
The two French presidential front-running candidates remain opposed on the issue, with socialist François Hollande in favour of assisted suicide and President Nicolas Sarkozy against it.