The US has provided nine rotary-wing aircraft in 2002 for monitoring of the Afghan border.
Officials said that the helicopters were part of air wing of the Ministry of Interior and played a vital role in combating militancy and drug trafficking.
"Pakistan decided to return the aircrafts after the two sides could not agree for their further use by Islamabad," sources said without giving any more details.
Initially four helicopters were returned on October 15 while the remaining five were loaded on a transport aircraft in Islamabad today and sent back.
US President Donald Trump had slammed Pakistan for its continued support to terrorist groups and warned Islamabad of consequences if it continues to do so while announcing his Afghan and South Asia policy in August.