Pope Francis is ordaining 19 men to the priesthood in St. Peter's Basilica.
Most of them are Italians, but other seminarians are from Croatia, Peru, Haiti and Japan.
Wearing white robes, the seminarians stood in three rows before the central altar after replying, "Here I am," as their names were called one by one.
Francis in a ritual asked if they were worthy to become priests.
During his homily, he told them to carry out their mission "in joy and charity" and to never "tire of being merciful" toward the faithful.
The seminarians' ages range from mid-20s to 46.
The ordinations come as the church and many of its clergy have lost credibility with rank-and-file Catholics after decades of scandals involving pedophile priests and systematic cover-up by bishops.