The 30 deaths in rural Eastern Cape province occurred during the annual season when young males undergo a rite of passage into manhood.
Ten other youths were hospitalised after being rescued from a forest on Sunday, said provincial health department spokesman Sizwe Kupelo in a statement.
"The ten initiates' private parts are rotten. They are badly damaged. Their condition is scary," he said.
A further 293 young men were undergoing hospital treatment for dehydration, gangrene and septic wounds, Kupelo added.
Some had lost their genitals.
Teenagers from ethnic Xhosa, Sotho and Ndebele groups typically spend around a month in secluded bush or mountains areas for their initiation to manhood.
This includes a circumcision as well as lessons on masculine courage and discipline.
Traditional surgeons perform the procedure in the bush, sometimes with unsterilised instruments or lacking in technique.
Botched circumcisions leading to penis amputations and deaths are an annual tragedy.
In May around 34 deaths in two other provinces were reported.
The ruling African National Congress said Sunday it was "distressed" over the latest deaths.
It called for basic medical training of the traditional surgeons to render "an entrenched and necessary part of our cultural fabric" safer.