Gilani accepted an invitation from his Indian counterpart Manmohan Singh to attend the match after a meeting with President Asif Ali Zardari on Saturday.
"I have decided to avail of this opportunity in national interest," an official statement quoted Gilani as telling a meeting of the federal cabinet in Islamabad.
"It is also a timely opportunity for the two governments to show to the world that the two nations can play together as well as sit and deliberate together on issues of national importance," he said.
A knock-out World Cup match on Indian soil is the biggest fixture between the rivals for decades and excitement is already at fever-pitch.
Wednesday's match in Mohali, being described as a "clash of titans," will also showcase one of the world's most intense sporting rivalries, fuelled by nationalism and a shared history.
Relations are still tense following the November 2008 Mumbai attacks that left 166 people dead and stalled a fragile four-year peace process between the two nuclear-armed South Asian rivals.
Top officials from India and Pakistan are holding talks in Delhi from March 28 focusing on counter-terrorism, narcotics control and humanitarian issues.
The two countries announced the resumption of peace talks last month after a meeting between Pakistani Foreign Secretary Salman Bashir and his Indian counterpart Nirupama Rao in the Bhutanese capital Thimphu.
COMMENTS (9)
Comments are moderated and generally will be posted if they are on-topic and not abusive.
For more information, please see our Comments FAQ