Believers hold that the fire is miraculously sent from heaven to ignite candles held by the Greek Orthodox patriarch in an annual rite dating back to the 4th century that symbolises the resurrection of Jesus.
Israeli public radio said around 10,000 faithful attended this year's ceremony, fewer than in recent years, as police were deployed around the church and in the streets of the surrounding Old City to keep the jubilation from getting out of hand.
Patriarch Theophilos III traditionally makes his grand entry at the head of a procession of monks, chanters, dignitaries and red and gold banners bearing icons.
After circling an ornate shrine in the heart of the church three times amid chants of "Axios" ("He is worthy"), he enters what Orthodox, Roman Catholics and many other Christians believe is Jesus's burial site, emerging minutes later with several lit candles.
The patriarch is always searched beforehand to ensure that he is carrying nothing, such as matches or a lighter, that could be used to light the candles.
As joyous people press in on him, the patriarch passes on the flames to their outstretched candles. The fire makes its way through the crowd, casting a flickering orange glow on the grey walls and towering stone columns, and filling the air with smoke.
Pilgrims claim the Holy Fire does not burn their hair, faces, clothes or anything else during the first 33 minutes of its appearance, and one web site (http://www.holyfire.org) offers videos claiming to show worshippers in prolonged contact with the flames without being hurt.
The Holy Fire, which quickly makes its way outside to the crowds waiting there, is also carried to nearby Bethlehem's Church of the Nativity, where Jesus is believed to have been born, and also much farther afield.
It will be flown to Athens and to the capitals of other predominantly Orthodox countries to be shared.
The church, which the Orthodox call the Church of Resurrection, also encloses what is widely believed to be Calvary, the site on which Jesus was crucified.