Arriving in the state government headquarters, Thackeray accompanied by wife Rashmi, a few family members, son Aaditya and others first paid homage at the Martyr's Memorial erected in memory of those who sacrificed their lives in the Samyukta Maharashtra Movement.
Uddhav and Aaditya Thackeray placed wreaths, bowed and paid obeisance at the memorial near Mantralaya.
Later, he also paid respects offered flowers before the portraits of B.R. Ambedkar, Chhatrapati Shivaji Maharaj and other historical figures, inside the Mantralaya.
Along with Thackeray, his six Cabinet colleagues comprising the Maha Vikas Aghadi - Shiv Sena's Eknath Shinde and Subhash Desai, NCP's Jayant Patil and Chhagan Bhujbal, and Congress' Balasaheb Thorat and Nitin Raut - also assumed charge in their respective chambers.
Later, he was due to have a brief meeting with his Cabinet colleagues in a meeting hall near his office after the mini-Cabinet met for the first time late on Thursday night.
Though the agenda of the meeting is not yet known, it is expected that the Chief Minister may make a few announcements signalling he's now firmly in the saddle.
Several thousand people had lined the road leading to Mantralaya with many others including staffers in and outside Mantralaya.
( With inputs from IANS )