Governor N.N. Vohra administered the oath of office to Mehbooba along with her council of ministers.
Meanwhile, former deputy chief minister Nirmal Singh also took oath.
Union Parliamentary Affairs Minister M. Venkaiah Naidu and Minister of State in the Prime Minister's Office (PMO) Jitendra Singh, among many others, were present during the swearing-in ceremony. The Congress Party boycotted the ceremony.
The Governor had yesterday invited Mehbooba to form and lead the PDP-BJP coalition government in the state.
The Congress has decided to stay away from today's swearing-in ceremony of the Peoples Democratic Party (PDP) chief Mehbooba as the first woman Chief Minister of the state.
They have termed the PDP-BJP coalition as 'unholy alliance'. The ceremony is scheduled to take place at 11 a.m. at the Raj Bhawan here.
A leader with grassroots-level popularity, Mehbooba Mufti turned Peoples Democratic Party into a regional force and emerged from the shadow of her illustrious father Mufti Mohammad Sayeed to head Jammu and Kashmir, the first woman Chief Minister of the state.
A law graduate, 56-year-old Mehbooba took a plunge into mainstream politics of the state in 1996 by joining Congress, along with her father, at a time when militancy was at its peak.
She is credited with growth of the PDP with some observers arguing that she outshone her father in connecting with the common people, especially the youths.
She was also accused of playing the soft-separatist card. PDP chose the green colour for the party flag and adopted Pen- Inkpot election symbol of the Muslim United Front (MUF) of 1987, but these moves found some resonances on the ground among the Kashmir residents.
Heading a PDP-BJP government formed with an alliance between two idealogical extremes, Mehbooba faces a challenging task ahead as she will strive to carry forward her father's 'healing touch' legacy.