The open-air ceremony took place in Beirut and included a call for peace in the Middle East in general and Syria in particular.
"Why so much death?" Benedict said. "I call on the international community and Arab countries to propose solutions which respect human rights."
The pontiff rallied Christians to be more active in working to ease the tensions that have run through the region. "I appeal to all of you to be peacemakers, wherever you find yourselves."
Vatican Radio said the setting for the mass included a centuries-old olive tree that tied Lebanon into the historical Holy Land. After he spoke, Benedict handed out communion for a hand-picked group of 30 pilgrims.
Security around the downtown mass was tight and the event went off without incident. The (Beirut) Daily Star said troops patrolled the streets and manned major intersections while helicopters kept an eye on the proceedings. A cadre of journalists and VIPs, including President Michel Sleiman, were part of the throng.
The pope returned to Rome at the end of the day.