Some pilgrims carried large wooden crosses as they walked down the Via Dolorosa, or Way of Sorrows, stopping at 14 stations that commemorate events that befell Jesus as he was led to his death.
Many pilgrims prayed in the ancient Church of the Holy Sepulcher, traditionally the site of Jesus' death, burial and resurrection. Some chanted hymns, while others prostrated themselves on a smooth stone slab marking the spot where Jesus' body was placed after being removed from the cross.
The crowd in one of the Old City's streets included two dozen members of an American church group from Ohio, dressed in white. Eileen Joiner, 43, from Akron, Ohio, said she was moved to be in Jerusalem. "You see a picture and it looks impressive. You see it in person and it's always so much more," she said.
The group's pastor, Janice Skeen, said a recent shooting attack in Jerusalem hadn't deterred them. "You can't escape the feeling and the presence of God here. This is his special land," she said.
The March 6 attack by a Palestinian gunman killed eight young students at a the Mercaz Harav yeshiva in the city.
Police said thousands of security personnel were deployed around Jerusalem because of Good Friday and the Jewish festival of Purim, which also falls this weekend. Jews celebrate Purim by dressing up in costumes and reading the Book of Esther, which recounts a victory by the Jews over their enemies in ancient Persia.
Police are also on high alert because of fears of a revenge attack for the February assassination of a high-ranking commander in the Lebanese militant group Hezbollah. Israel denied involvement, but Hezbollah threatened to avenge his death with an attack on Israeli targets. Police spokesman Micky Rosenfeld said the alert level Friday was one below the maximum.
Other visitors in evidence in Jerusalem hailed from Spain, Poland, the Philippines, Brazil, and several African nations, some wearing traditional costumes.