Cardinal Gianfranco Ravasi, head of the Vatican's Pontifical Council for Culture, said several leading world scientists attended on Thursday including Britain's John Gurdon, winner of the Nobel Prize for Medicine last year.
Ravasi said the showed the Church did "not intervene only negatively" in the debate on stem cell research and its commitment to finding cures was not only "words".
The cardinal said he would personally present Pope Francis with the results of the three-day conference, which will include examples of successful therapy using adult stem cells.
The conference follows a similar one held in November 2011 and like the previous one it is being organised together with the US laboratory NeoStem, headed up by Robin Smith, who is also president of the "Stem for Life Foundation".