Nipul Bora, a hardcore ULFA militant and self-styled commander of the outfit on Wednesday surrendered before Sonitpur District Superintendent of Police Satyen Gogoi in Tezpur.
He submitted a sophisticated 56 bore pistol and two magazines with 13 rounds of ammunition.
Bora, also known as Bijoy Lahon alias Pulin Hazarika, was in charge of the ULFA's general headquarters in Bhutan, police said.
"This is the fifth surrender since last month," Gogoi said adding Bora joins Ranu Gohain, Uttam Medhi, Uttam Kakoty and Bhabesh Saikia.