“This is just a little step, just a little democracy,” Mr. Min Zaw said. The National League for Democracy will have at best a small minority in Parliament, he said. But “the future is brighter than ever.”

Secretary of State Hillary Rodham Clinton, in Istanbul for a meeting on Syria, welcomed Sunday’s vote in Myanmar, also known as Burma.

“It is too early to know what the progress of recent months means and whether it will be sustained,” Mrs. Clinton said. “There are no guarantees about what lies ahead for the people of Burma, but after a day responding to a brutal dictator in Syria, who would rather destroy his own country than let it move toward freedom, it is heartening to be reminded that even the most repressive regime can reform and even the most closed society can open.”

Hundreds of foreign journalists and numerous teams of foreign monitors were allowed into Myanmar to witness the voting, a contrast to previous years when a hermetic military government tried to keep out prying eyes.

The European Union and the United States have said that the fairness of the outcome will be crucial in determining whether they lift their economic sanctions against the country.

Ms. Aung San Suu Kyi and other officials from her party complained of a litany of “irregularities” during the campaign, but the alleged infractions — defacing of posters and campaigning by government officials on behalf of the ruling party in contravention of Myanmar’s Constitution — appeared minor compared with the harsh treatment of the opposition in years past.