Having carried the Flag for South Africa at the Opening Ceremony of the 2012 Summer Paralympics, Oscar started his Paralympic campaign with a new world record in the 200m, in a time of 21.30s.
Later, he was defeated in the final the next day by Alan Oliveira of Brazil. Pistorius took silver, and then created a controversy by complaining about the length of Oliveria's blades. He later apologised for the timing of his remarks, but not the content of his complaint.
Pistorius won a gold medal on 5 September running the anchor leg as part of the South African 4 × 100 metres relay team. The team set a world record time of 41.78 seconds. He was unsuccessful in defending his Beijing Olympics 100 metres title when he came fourth with a season's best time of 11.17 seconds, and the race was won by Great Britain's Jonnie Peacock. On 8 September, the last full day of competition, Pistorius won gold in the T44 400 metres with a time of 46.68 seconds, breaking the Paralympic record.