Acting Chief Justice of Rajasthan High Court Sunil Ambwani administered oath to Naik, an official release said.
Before it, state Chief Secretary Rajiv Mehrishi read out the warrant of appointment. Naik was also given the guard of honour.
The ceremony was attended by Chief Minister Vasundhara Raje, Assembly Speaker Kailash Meghwal, members of the council of ministers, state former Chief Minister Ashok Gehlot and other leaders and officers, it said.
Naik was given additional charge of Rajasthan after Margaret Alva completed her term on August 5.