Allegation comes days after similar move by India, which accused six Pakistani diplomats of being part of a spy network.
Pakistan has accused eight Indian embassy employees of involvement in spying and "terrorism" but stopped short of expelling them, in the latest apparent tit-for-tat move as relations between the two countries deteriorate.
The declaration on Thursday came days after a similar move by New Delhi, which accused six Pakistani diplomats of being part of a spy network, forcing Islamabad to withdraw them from their posts.
"A number of Indian diplomats and staff ... have been found involved in coordinating terrorist and subversive activities in Pakistan under the garb of diplomatic assignments," Nafees Zakariya, spokesman for Pakistan’s foreign ministry, told a press briefing in Islamabad.
He went on to name the eight men, including one accused of using a false identity to pose as an employee of a Pakistani mobile network.
"All these eight officials were involved in espionage, subversion and supporting of terrorist activities," he said.
New Delhi rejected the allegations, calling them "baseless and unsubstantiated".
"We completely reject the baseless and unsubstantiated allegations made by Pakistan against certain officials of Indian High Commission in Islamabad," Vikas Swarup, foreign ministry spokesman told reporters in New Delhi.
"The allegations against the Indian officials represent an afterthought and a crude attempt to target these officials for no fault of theirs," he said.
Tensions between the nuclear-armed neighbours have soared since a raid last month killed 19 soldiers on an Indian army base near the de facto border dividing the disputed Kashmir region, the worst such attack in more than a decade.
India blamed fighters in Pakistan and said it had responded by carrying out strikes across the heavily militarised border, although Islamabad denies that these took place.
Cross-border shelling between the two countries has led to at least 14 civilian deaths in November alone.
Tensions were already high before the army base attack, with nearly 90 people killed in clashes with security forces in Indian-administered Kashmir over the death of a popular rebel leader in July.
Kashmir has been divided between India and Pakistan since their independence from Britain in 1947. Both claim the territory in full and have fought two wars over the mountainous region.
The latest round of diplomatic expulsions began on October 27 when India detained a Pakistani visa official accused of spying, later declaring him persona non grata and sending him home.
Pakistan responded with a similar move the same day.
- Pakistan claims Indian diplomats in Islamabad were part of an alleged spy network