The Kloof Driefontein Complex (KDC) mine's West section was reopened on Monday after being closed because of a lethal fire, said Gold Fields Limited.
Spokesman Willie Jacobsz said the West section opened for a full first shift on Monday morning.
"It was reopened after an agreement was reached with the department of mineral resources," he said.
Some sections of the complex were closed after a fire broke out in the Ya-Rona shaft in Merafong, near Carletonville, west of Johannesburg on June 30.
Five miners were killed and 14 were injured.
Jacobsz said the Ya Rona Shaft would remain closed until further notice, in accordance with a Section 54 order by the mineral resources department.
"The fire at the Ya Rona Shaft has not yet been extinguished and proto teams [underground rescue teams] continue to attend the scene," he said.
The mine's East section was reopened on Wednesday.