The index, which gauges manufacturing activity in Africa's most industrialised economy, rose to 50.7 in December from 49.5 in November, above the 50 mark that separates contraction from expansion.
New orders and business activity were at their highest level in 2018 last month, but the survey's employment sub-index slumped to its lowest since 2014.
"While the December survey results are encouraging, a sustained recovery in demand is required before a meaningful recovery in manufacturing output, investment and employment can take place," economists from the Bureau for Economic Research, which conducts the survey, said in a statement.
The South African economy is staging a gradual recovery after falling into recession last year. Stronger manufacturing growth in the third quarter was one of the main reasons why the economy exited recession.
(Reporting by Alexander Winning, editing by Larry King)
