The rally in Multan city was lead by Father Shahzad Tanvir, Father Naeem Javed and former provincial lawmaker Naveed Aamir Geva, who is the secretary general of the All Pakistan Minorities Alliance.
The protestors carried banners and placards and shouted slogans against the police.
Addressing the rally, Geva said "fake cases" had been registered against Bishop Leu Paul at a police station in Mian Chanu on November 2.
The protestors appealed to Punjab Chief Minister Shahbaz Sharif to take notice of the issue.