Deputies in the new-look Verkhovna Rada chamber sang the national anthem before holding a minute's silence in memory of those killed in Kiev protests and the conflict in east Ukraine.
They then read in unison an oath to serve the Ukrainian people.
Lawmakers looked set later today to confirm current Prime Minister Arseniy Yatsenyuk, who will remain in his post at the head of a new pro-Western coalition hammered out after weeks of haggling.
The coalition has sworn to stick to Ukraine's pro-Western trajectory in the face of Russian support for a bloody separatist conflict in the east and pledged to pass a law confirming Kiev's desire to join NATO.
Over 4,300 people have been killed in the fighting between pro-Moscow rebels and government forces since April.
The crisis has sent relations between Russia and the West to their lowest ebb since the Cold War.