Lieutenant Governor Najeeb Jung administered the oath of office and secrecy to Kejriwal and six other ministers at the Ramlila Maidan here.
Six ministers -- Manish Sisodia, Somnath Bharti, Rakhi Birla, Satyendra Jain, Saurabh Bharadwaj, Girish Soni -- also took oath of office and secrecy at the ceremony.
After the ceremony, Kejriwal would visit Mahatma Gandhi's memorial Rajghat to pay homage.