The newly-elected legislators took oath on the first day. Chief Minister K. Chandrasekhara Rao was the first to take oath followed by ministers.
Earlier, senior Congress legislator K. Jana Reddy was sworn in as the pro term speaker by Governor E.S.L. Narasimhan at Raj Bhavan.
The speaker will be elected Tuesday while the governor will address the joint session of both houses the next day. The session will continue till June 13.
The Telangana Rashtra Samithi (TRS) bagged 63 seats in the 119-member assembly in the recent elections.
Telangana came into existence as the 29th state June 2 and the same day Chandrasekhara Rao took oath as the first chief minister.