A military statement said Dadullah and his men were "trying to enter Pakistan" across the border.
Mansour Dadullah had succeeded his elder brother, Mullah Dadullah, a senior military commander who was killed in an Afghan and Nato operation in southern Afghanistan in May 2007.
The Taliban said in a statement last December that they had sacked the commander "because he disobeyed orders of the Islamic Emirate" of the Taliban.
But a spokesman for the commander denied that he was fired, leading to speculation of infighting among the movement.
Monday's operation is believed to be the first time Pakistan has admitted to Afghan Taliban leaders such as Dadullah having a presence in the country.
Speaking from Quetta on Monday, Saud Gohar, the provincial police chief, told AFP news agency: "[Dadullah] has been wounded and arrested early this morning.
"He is in the custody of the security agencies along with five accomplices. They are all injured"
Major General Athar Abbas, chief military spokesman
"We had reports of his presence from intelligence sources."
He said the operation was carried out jointly by police and anti-terrorist forces.
Major General Athar Abbas, chief military spokesman, told the AFP news agency: "He is in the custody of the security agencies along with five accomplices. They are all injured
"They were intercepted and chased by security forces at a frontier constabulary post near the Afghan border."
The arrest comes a day after Robert Gates, the US defence secretary, said that Taliban and al-Qaeda fighters in the country's border regions posed a direct threat to the Islamabad government.
Pakistan on Saturday dismissed a senior but unnamed US official's assertion that Mullah Omar, the Taliban commander, and al-Qaeda leader Osama bin Laden were operating from regions along the Afghan border.