There were no festivities to accompany the final, long-awaited step in the establishment of full diplomatic relations between the two countries for the first time in their 60 year history.
Charge d'affaires Rami Mourtadaha drew back a curtain to reveal the plaque: "The Embassy of the Lebanese Republic." The building sits near the U.S. Embassy on the Syrian capital's upscale Abu Rummaneh street.
Michel el-Khoury, currently Lebanon's Ambassador to Cyprus, was expected to start his new mission in Damascus in the middle of April.
No Syrian officials attended the opening ceremony and no speeches were made. Syrian media took very little notice of the opening. State-run news agency SANA — which generally reflects the thinking of the government — mentioned the inauguration, but in few words.
Syrian Foreign Minister Walid al-Muallem blamed the notable official absence on a scheduling conflict.
"It was not intentional," he told a joint news conference with visiting Arab League secretary-general Amr Moussa at the end of day-long Arab Foreign Ministers' meeting on the Middle East peace process.
"We had learnt first the inauguration was taking place on Sunday, not Monday," he said.
Later Monday night, Syrian Vice-Foreign Minister Faisal Miqdad paid a courtesy visit to the embassy.
"I have come here to greet the Charge d'affaires and the Lebanese staff at the embassy. Our real hope is that the two embassies, the Syrian in Beirut and the Lebanese in Damascus, will be genuine channels for strengthening and boosting direct relations between the two countries," Miqdad said.
Syria, which withdrew its forces from Lebanon in 2005, after a 29-year presence, opened an embassy of its own in West Beirut last December, as ties between the two long-feuding neighbors slowly improved.
Damascus has not yet named an envoy. Politicians in Beirut, along with the U.S. and other Western nations, have been pressing Lebanon hard to establish diplomatic ties with Syria.
The two countries have not had diplomatic relations since Britain and France carved them out of the remnants of the old Ottoman Empire in the 1940s.
Lebanese Foreign Minister Fawzi Salloukh told the Assafir newspaper the opening of the embassies would help, "organize and legalize bilateral relations, and become a guarantee for Lebanese citizens in Syria and Syrian citizens in Lebanon."
Syria dominated Lebanese politics for 30 years, until the assassination of former Lebanese Prime Minister Rafik al-Hariri in 2005. His murder sparked days of massive protests in Lebanon and led to the eventual withdrawal of Syrian forces.
Some countries suspect that elements in Damascus were behind the killing. Syria has consistently denied any involvement.