The Taliban troops were killed during an operation by the International Security Assitance Force (Isaf) and Afghan troops in Helmand province’s Greshk district on Saturday, the Afghan defence ministry said.
"As a result of Isaf air bombardment and a joint ground operation, 40 enemies of our people were killed," a statement said on Sunday.
A Taliban stronghold was destroyed in the raid; but no Afghan or foreign troops sustained any casualties, it added.
In a separate statement, the ministry announced the capture of 21 suspected combatants across southern and eastern Afghanistan.
Eight other men were captured in southern Zabul accused of having links with the Taliban, which was removed from power in a US-led offensive five years ago.
"As a result of ISAF air bombardment and a joint ground operation, 40 enemies of our people were killed"
An Isaf statement
Sixteen of the fighters were seized in "clearance operations" in the eastern town of Khost on Saturday, the statement said.
Afghan forces arrested five others a day earlier in neighbouring Paktia province, which borders Pakistan.
Hakim Taniwal, the governor of Paktia, was assassinated by a Taliban-linked suicide bomber on September 10.
About 18,500 troops are currently deployed in Afghanistan; but commanders have requested more soldiers, as well as helicopters and transport aircraft, to take on the Taliban.
Taliban fighters have stepped up the intensity of their attacks against Nato and Afghan forces this year, carrying out well planned operations against troops while continuing their campaign of suicide and roadside bombings.