The session was the first time President Mwai Kibaki and opposition leader Raila Odinga were in the same room since Odinga accused Kibaki of stealing the Dec. 27 vote. More than 600 people have died in rioting and tribal unrest.
Odinga has rejected an invitation from Kibaki for direct talks to resolve the dispute, and mediation efforts have stalled.
Security was tight, with soldiers deployed around the building and CBS News reporter Katherine Arms reports some roads around parliament were blocked off. Riot police were deployed along nearby thoroughfares.
Opposition and government members of parliament greeted each other and chatted amicably before the session began, then both sides stood and applauded when Odinga walked in. Kibaki received a cool reception: Odinga and his supporters remained seated, not clapping as the president arrived.
Odinga's party spokesman, Ahmed Hashi, said that attending the parliament session convened by the president "does not mean recognizing the presidency of Kibaki."
The main business of the day was voting for a new speaker.
Kenneth Marende, a 52-year-old opposition lawyer, received 105 votes, to 101 for the president's candidate. The speaker cannot directly block the president's agenda, but he can slow it down with his rulings and allow motions against the president's agenda to be debated.
While the opposition had the most seats in parliament, neither party had had the two-thirds majority needed to elect the speaker in a first round vote, meaning both had to court legislators from minority parties during the first parliament session since the Dec. 27 general election. Marende was elected on the third vote.
A week of violence after the vote killed at least 612 people and displaced hundreds of thousands, a government commission said. The crisis has crippled the country's billion-dollar tourist industry.
The voting for a new speaker was delayed by the tension. Odinga supporters argued the balloting should not be secret, as is traditional. Lawmakers later agreed the vote should be secret, ripped up a couple of dozen ballots already cast, and held the vote again.
"We went into (the presidential) election with secret ballots and you stole it," said William Ruto, a top opposition party official who had sought open balloting.
Former U.N. Secretary-General Kofi Annan was expected in Nairobi Tuesday night on a mediation mission, but the visit was postponed several days after Annan fell ill with the flu, his office in Geneva said Tuesday.
Odinga has called for three days of protests across the country to start Wednesday in 41 locations in defiance of a government ban. Similar protests earlier this month shut down Nairobi and homes in the city's packed slums were set ablaze by rival ethnic groups.
In Nairobi's Mathare slum Tuesday, a crowd that had gathered outside a house that had caught fire due to an electrical fault started chanting pro-Odinga slogans when journalists were spotted. Members of Kibaki's Kikuyu tribe who tried to pass through the crowd were kicked and punched.
"The police will shoot tomorrow, but they don't have a bullet for each of us," said Cliff Owino as he picked up a lump of cement and aimed it at a fleeing Kikuyu. "These will be our bullets. This is how the war starts."
Also Tuesday, the U.N. World Food Program distributed food supplies, some from the government, to around 77,000 people from Nairobi's Kibera slum.
Arms reports this is the second time in a week that the WFP has done a food distribution in the slums, and adds that things got tense last time because there were more people than there was food.