The evening basilica service began in darkness. Then the basilica's cavernous interior was suddenly bathed in light, reflecting the Christian beliefs that Jesus rose from his death by crucifixion and that goodness can triumph over evil.
The 86-year-old pope is recuperating from bronchitis, which saw him recently hospitalised for three days.
On Sunday, tens of thousands of faithful are expected to join the pope in St. Peter's Square for Easter Mass and to listen to his speech about conflicts in the world at the end of Holy Week.
At the start of the Easter vigil, Francis, who arrived in a wheelchair he uses to cope with knee pain, incised in the wax of a tall candle a cross, the first and last letters of the Greek alphabet - alpha and omega - and the numerals of this year.
Then the lit candle was carried by a cleric up the basilica's centre aisle, past darkened pews filled with faithful. Dozens of cardinals and other prelates followed, each carrying a smaller, lit candle.
"The Church calls upon her sons and daughters, scattered throughout the world, to come together to watch and pray," Francis said, beginning the service on Saturday.
The basilica Mass during the vigil of Christianity's most important day has become an occasion for pontiffs to baptise several adults from around the world.
Selected to be baptised at this year's vigil were eight believers, from Albania, the United States, Nigeria, Italy and Venezuela, the Vatican said.
