"The European Commission has reinstated the Viracept marketing authorization following its suspension earlier this summer," said a company statement.
On August 7, the European Commission suspended the licence due to the toxic contamination of some Viracept tablets, which Roche announced when it began a massive recall of the drug in June.
Tests had confirmed the presence of ethyl mesylate sulphonate (EMS), which is toxic to humans.
William M. Burns, chief executive of Roche's pharmaceuticals division, welcomed the decision.
"Our teams have worked diligently in manufacturing and in close collaboration with the health authorities, health care providers, NGO treatment providers and patient groups on the recall with the full intention of re-supplying this medication," he said.
Viracept has been on the market since 1999.
On Tuesday, Roche announced strong results for the first nine months of 2007, with a 12-percent jump in its turnover to 33.9 billion Swiss francs (20.2 billion euros, 28.7 billion dollars).