The parliament gave the government the mandate last October and since December 2007 the Turkish army has carried out a total of 29 airstrikes and cross-border military operations in northern Iraq, targeting suspected PKK bases.
An overwhelming 511 lawmakers in the 550-seat legislative body backed the motion to extend the mandate, which expires October 17.
Despite Iraqi protests, Ankara insists that the strikes are only aimed against the terrorist PKK group, not against "the territorial unity and stability of Iraq."
According to the Turkish General Staff data, there are some 3,500 Kurdish insurgents in northern Iraq.
The Turkish leadership is set to meet Thursday to discuss further measures against the rebel group. The opposition earlier proposed to set up a military buffer zone inside northern Iraq along the border to stop rebel infiltrations.
The PKK, considered a terrorist organization by the EU, the United States, and many other countries, has been fighting for an autonomous ethnic Kurd state in southeast Turkey for nearly 25 years. The conflict has claimed over 40,000 lives.
