The Pope is set to host a rare meeting of more than 100 cardinals from around the world for discussions on policy.
The clerical sex abuse scandal is expected to be high on the agenda, along with concern over the persecution of Christians in some countries.
They will also discuss the decision to invite disaffected Anglican bishops and priests to join the Catholic Church.
The talks will be followed by the elevation of 24 new cardinals in Pope Benedict XVI's third consistory.
The cardinals are rarely summoned to the Vatican in such numbers, and all 179 of them would only be expected to gather for a conclave - the meeting following the death or abdication of a pope to elect his successor. The number of voting cardinals at a conclave - those aged under 80 - is 121.
But Pope Benedict has been attempting to create more opportunities for the cardinals to discuss important issues.
The event has been described by analysts as a pre-conclave, enabling the cardinals to see who could potentially succeed the German Pope.
Vatican spokesman Fr Federico Lombardi said no major developments were expected at Friday's talks.
"We're talking about communication, information, clarification and reflection on some issues, but certainly not a highly developed in-depth discussion," AP quoted him as saying.
However, the cardinals are expected to discuss the Church's response to the sex abuse scandal, amid criticism that it has not done enough to compensate victims or address the problems raised.
BBC News
