The Cairo meeting ended in scuffles, a walkout and failure to establish a joint united front organization to oppose President Bashar Assad's regime.
When a Syrian Kurdish group walked out, remaining delegates cried "scandal, scandal."
Abdel Aziz Othman of the National Kurdish Council said of his delegation's decision to leave: "The Kurds withdrew because the conference rejected an item that says the Kurdish people must be recognized. This is unfair and we will no longer accept being marginalized."
Abdel-Aziz al-Khayyar, who spent 14 years in Syrian prisons and is now part of the Syrian National Coordination Body, commented: "It's very dangerous at this point. If we fail to unify as the opposition, it is the greatest gift to the regime," Day Press news agency reported Wednesday.
Al-Khayyar said of those advocating foreign military intervention were "voices that are not very important ... waiting for the world to give its kids to die for our cause."