The militants attacked the check post with rockets and automatic weapons, killing a soldier and injuring five more.
The security forces repulsed the attack and killed 18 militants, state-run PTV reported. The troops called in helicopter gunships to provide air support.
The helicopters shelled militant positions in the mountainous Dabori region of Orakzai tribal agency and destroyed four bunkers.
Sixteen militants were also injured in the fighting, the report said. The report could not be independently confirmed as journalists are barred from travelling to the area. Orakzai, a former stronghold of the Taliban, is the only one of Pakistan's seven tribal regions that does not border Afghanistan.
Pakistani forces conducted a major operation against the Taliban in Orakzai in March last year. The troops declared an end to the military offensive in June after announcing that the region had been fully cleared of Taliban.
However, local residents claim that while the lower part of Orakzai has been cleared, the situation in the central and upper parts has not changed much.