On a month-on-month basis, consumer inflation was at 0.4% in December compared to 0.3% in November. Analysts polled by Reuters had expected it to stay at 0.3%.
However, in better news, core inflation, which excludes prices of food, non-alcoholic beverages, fuel and energy, was at 4.9% year on year in December, from 5.0% the previous month.
On a month-on-month basis core inflation was at 0.2% in December, compared to 0.1% in November.
Price pressures have been gradually easing in Africa's most industrialized economy, after inflation struck a 13-year high of 7.8% year on year in July.
The South African Reserve Bank has raised interest rates to fight inflation at its last seven monetary policy meetings since its latest tightening cycle began in November 2021.
The central bank, whose next rate-setting decision is due on Jan. 26, targets inflation of between 3% and 6%.