Taliban commander Mullah Mansoor was killed in a gun battle with security forces, state-run Radio Pakistan quoted official sources as saying.
Other media reports said Mansoor succumbed to injuries sustained during a clash between security forces and militants in Dir region of Khyber-Pakhtunkhwa province, which has witnessed cross-border attacks by Pakistani Taliban fighters based in Afghanistan.
Mansoor was taken to a hospital in Afghanistan, where he died.
TV news channels quoted their sources as saying that 34 terrorists were killed in three days of fighting in the Dir area.
Mansoor belonged to Khaal area of Dir.
During a recent attack in Dir area, Taliban fighters captured and beheaded 17 Pakistani soldiers.
They later issued a gruesome video that showed the 17 heads lying on a white sheet.
The video contained an audio recording by Tehrik-e-Taliban Pakistan chief Hakimullah Mehsud, who said his fighters would continue to battle the Pakistan Army until the government stops supporting the US and enforces Shariah or Islamic law in the country.