Gold Fields says that South Africa's power crisis will see quarterly gold production fall by between 20% and 25%.
The world's fourth-largest gold miner said that scaling back production would put 6,900 jobs at risk.
South Africa's mines were forced to suspend production for five days in January as power cuts raised fears that miners could get trapped underground.
Since then, mining companies have been operating with 10% less electricity than they would normally use.
In last week's South African budget, state-owned Eskom was allocated 60bn rand ($7.6bn, £3.9bn) over the next five years to tackle the power cuts.
"The inability of Eskom to supply the mines their full power requirements has caused a significant crisis in the South African mining industry," said Terence Goodlace, the head of Gold Fields South Africa operations.
"It is paradoxical that we have to consider downscaling in the current record-high gold price environment," he added.
