On a month-on-month basis, consumer inflation rose to 1.0% in March from 0.7%.
Core inflation, which excludes prices of food, non-alcoholic beverages, fuel and energy, was at 5.2% year on year in March, the same as in February.
Month-on-month core inflation was at 0.8%, also unchanged.
Analysts polled by Reuters had predicted a drop to 6.9%.
Inflation has remained stubbornly high in Africa's most industrialized economy since peaking in July 2022 at 7.8%, leading to a run of interest rate hikes from the central bank.
At its last meeting in March, the South African Reserve Bank (SARB) surprised analysts with a larger-than-anticipated 50 basis point hike.
The SARB targets inflation between 3% and 6%.
