Iran has some of the highest execution rates in the world
At least eight women and one man are reported to have been sentenced to death by stoning in Iran.
The group, convicted of adultery and sex offences, could be executed at any time, lawyers defending them say.
The lawyers have called on the head of Iran's judiciary to prevent the sentences from being carried out.
The last officially reported stoning in Iran last year drew strong criticism from human rights groups and the European Union.
The eight women sentenced, whose ages range from 27 to 43, had convictions including prostitution, incest and adultery, Reuters news agency reported.
The man, a 50-year-old music teacher, was convicted of illegal sex with a student, reports said.
Under Iran's Islamic law, stoning to death is the punishment for the crime of adultery.
In 2002 Iranian judiciary chief Ayatollah Mahmoud Hashemi Shahroudi imposed a moratorium on stoning, but at least three people are reported to have been executed by stoning since then.
Shadi Sadr from the Volunteer Lawyers' Network, which is representing the women, said: "We are very worried as there are at least eight women and one man with a definitive verdict which can be carried out any moment.
"There are no guarantees that the punishments will be halted or commuted."
She called on the international community to back their efforts, adding: "We are in close touch with human rights organisations and many of them have supported our campaign."
Fellow defence lawyer Mariam Kian-Arsi said: "Our specific and clear demand is to have the stoning sentence stopped by Ayatollah Shahroudi since the defendants are liable to be stoned at any moment."
Women 'poorly represented'
In theory the penalty of stoning to death applies to both men and women.
But the lawyers say that in practice, many more women than men receive the sentence because they are less well educated and often poorly represented in court.
Human rights group Amnesty International earlier this year called on Iran to abolish "this grotesque punishment" and said many facing execution by stoning were sentenced after unfair trials.
Under Iran's strict penal code, men convicted of adultery should be buried up to their waists and women up to their chests for stoning. The stones used should not be large enough to kill the person immediately.