The Revenue Service said Africa's biggest economy imported 417,000 tons of Iranian crude in February, a dramatic reversal of a declining trend seen since October, when it imported 467,000 tons.
South Africa has come under Western pressure to cut Iranian crude imports as part of sanctions designed to halt Tehran's civilian nuclear program.
South Africa's trade and customs data showed Iranian crude imports at a monthly average of $280 million last year.
Iran has been South Africa's biggest crude supplier, accounting for a quarter of its oil imports.
Last week, the world's five fastest growing economies - including Brazil, Russia, India, China and South Africa (BRICS) - lashed out at the US-led West for its hostile and unilateral policies against Iran, and called on the western powers to try talks with Tehran over the latter's nuclear program.
The declaration issued at the end of the one-day BRICS summit in New Delhi came close to condemning the West's pressure tactics to make other countries obey its latest restrictions on trade ties with Iran, specially in the energy sphere. Saying that a conflict would have disastrous consequences, it wanted the two antagonists to resolve suspicions over Iran's nuclear program through talks on multilateral fora.