Antibiotics, non-prescription painkillers and medications for heart conditions and diabetes will all be subject to the price rise, health minister Channa Jayasumana said.
It is the second time in six weeks that pharmaceutical prices have been raised. In mid-March a 30 per cent increase was imposed.
Industry officials said the latest hike was necessary to offset the impact of fuel prices, which have doubled since December.
Official figures released Friday showed Sri Lanka's inflation rate at nearly 30 per cent in April, a seventh consecutive record high.
Sri Lanka has run out of foreign currency to import sorely needed essential goods.
The government this month announced a default on its $51 billion foreign debt and asked citizens abroad to donate money to help the island out of its economic predicament.
Sri Lanka has asked for an International Monetary Fund bailout, which could take up to three months to arrive.