"I believe the great danger has passed," Samaras said in an interview with the To Vima weekly on Sunday. "Drachmaphobia seems to have receded completely."
But Samaras, whose three-party government faces another reform hurdle in parliament next week, warned the nation: "There can be no letup in our effort because there is the risk of a relapse."
The government last week pushed through a tax bill introducing new annual income thresholds for salaried taxpayers and scrapping tax breaks for the self-employed, a category blamed for a large part of the tax evasion that has plagued state finances for decades.
On Monday, it will seek approval for another round of reforms tied to Greece's next slice of EU loans.
The opposition has condemned the measures as a new attack on the embattled middle class which is bearing the brunt of a fourth straight year of austerity.