"The retailer has now extended the pilot to a further 29 stores for testing with customers, with the intention to roll it out to all stores in the coming months," the company said in a statement.
The pilot launched five months ago initially included 10 locations.
"Increasingly cryptocurrency is being used by those under-served by traditional banking systems, or by those wanting to pay and exchange money in a cheaper and really convenient way," Pick n Pay said.
Weeks after the country's financial watchdog, Financial Sector Conduct Authority (FSCA), declared crypto assets a financial product, supermarket chain Pick n Pay said it was expanding a pilot allowing shoppers to pay for their groceries with bitcoin.
Under the system piloted by Pick n Pay, in partnership with crypto firms Electrum and CryptoConvert, customers can pay with bitcoin at till points through a smartphone app.
Pick n Pay is South Africa's second-largest grocery retailer with more than 500 supermarkets. It is also found in other southern African countries such as Botswana, Mozambique, Zambia, Zimbabwe, Lesotho, Namibia and Mauritius.