Prime Minister Narendra Modi arrived here on Thursday to attend 'Prakash Utsav', marking the 350th birth anniversary of Guru Gobind Singh, officials said.
Modi reached Patna in an Indian Air Force aircraft, Senior Superintendent of Police Manu Maharaj said.
The Prime Minister will return to Delhi later in the day. He was received by Governor Ramnath Kovind and Chief Minister Nitish Kumar.
Modi will offer prayers and serve 'langar' also.
Punjab Chief Minister Parkash Singh Badal and a large number of Sikhs from India and abroad will also take part in the event. He will also issue a postal stamp of Guru Gobind Singh.