The total area under poppy cultivation was about 224,000 hectares (553,500 acres) in 2014, a seven percent increase on last year, according to the annual Afghanistan Opium Survey released by the United Nations Office on Drugs and Crime (UNODC).
Just 74,000 hectares was being used to grow poppies in 2002, a year after the Taliban regime was toppled.
Despite a decade of costly US and international counter-narcotics programmes, poppy farming has boomed in the south and west regions, which include the most volatile parts of the country where the Taliban insurgency is strongest.
With US-led NATO troops withdrawing from Afghanistan, fears are rising that worsening instability could trigger further growth in opium cultivation as Afghan security forces struggle to push back the resurgent Taliban.
Poppy farmers are often taxed by the Taliban, who use the cash to help fund their insurgency against government and NATO forces.
"The country is having to stand on its own feet (and)... will have to deal with this criminalisation of its economics and politics as a matter of priority," Jean-Luc Lemahieu, director of policy analysis at UNODC, said.