Traian Basescu was due to attend a summit for European cooperation in southeastern Europe in Chisinau on June 5.
In a statement late Wednesday, his office said the president's participation is "no longer current," due to the violent riots that erupted after the opposition claimed Moldova's April 5 elections were rigged.
Moldovan President Vladimir Voronin accused Romania of trying to overthrow his government in organizing the protests in which at least two people died. Romania denied the accusations. Almost 80 percent of Moldovans are ethnic Romanians.