Snack company Simba has warned retailers that due to high winter rainfall,supplies will be affected and it asked for understanding as it "may not meet the expected levels of service over the next few weeks".
Currently, the company is only able to meet 70 percent of food giant Pick n Pay's demand.
Pick n Pay's food merchandise director Kevin Korb told Business Report: "We have spoken to Simba and they have confirmed that due to the recent rains, and the resulting shortage of good-quality potatoes, their Cape Town plant is currently battling to meet demand."
Some experts also say the shortage may be down to last year's low potato price and the increased cost of production - which encouraged many farmers not to plan the crop.
The wholesaler Makro is also experiencing shortages.
Preview: processing lines requirements for exotic #potato shapes http://t.co/DF9HTjDzKy
@PotatoCouncil's action to support #Scottish #potato industry: http://t.co/dtDUfnSmD2