Karni Mata fair constitutes a grand celebration at Deshnok town in Bikaner district of Rajasthan. Karni Mata temple forms the main venue of the fair which is organized twice a year for ten days. The first fair is larger and is held in the months of March-April during Navaratri from Chaitra Shukla Ekam to Chaitra Shukla Dashmi. The second fair is also held during Navaratri, but in the months of September-October from Ashwin Shukla Ekam to Ashwin Shukla Dashmi.

Mythology of Karni Mata
Karni Mata, an ascetic of 15th century, was known for leading a righteous life serving mankind. She dedicated her life for the betterment of poor downtrodden folks belonging to all communities. She was believed to possess supernatural powers and had laid the foundation of Deshnok. Since long she is regarded as the patron deity and is worshipped by her principal followers, known as Charans, and the rulers of Bikaner as goddess. Karni Mata fair is celebrated in commemoration of the goddess. The ostentatious fair is attended by a sea of devotees who visit the temple to seek the blessings of Karni Mata.

Features of Karni Mata Fair
During the fair the temple gate opens at 4 am in the morning for the devotees. Karni Mata temple is also known as Rat temple since numerous rodents roam freely in the vicinity of the temple. In fact if a rat or two runs over the feet of any devotee, it is considered auspicious for him. These sacred rodents are called as the `Kabas` and spotting a white `Kaba` is considered to be a difficult yet propitious task. Myths say that Karni Mata had brought one of his sons in the form of a mouse, after his death. Thus devotees often offer food to the `Kabas` and seek their blessings. During the fair, the rites and rituals of the temple is performed by the Charan priests. `Mangla-ki-Arti` is done initially which is followed by a `Bhog` to worship the deity. Two kinds of offerings are made by the devotees during the fair. The first one is `dwar-bhent` meant for priests and the workers and the second one is `kalash-bhent` which is used for the temple maintenance and development. Karni Mata is the patron deity of the royal house of Bikaner and thus the fair attains an imperial ambience with the presence of the royal family of Bikaner who visit the fair to pay their obeisance. The fair holds a special significance for the Rajasthani Hindus who attend the fair in large numbers.